Improvements in Furnaces.
Year: 1896

page_text: Date of Application, 20th July, 1896-Accepted, 27th Mar., 1897
Improvements in Furnaces.
I, JEAN WAGNER of No. 29 Rue du Chateau d'Eau, Paris, in the French
Republic, Civil 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:-
an
The present invention relates to improvements in furnaces. It comprises an
apparatus for the rational distribution and regulation of the air currents;
apparatus for regulating the air supply under the grate according to whether the
furnace is worked with natural draught with slow combustion or by artificial draught
with forced combustion; an improved mechanical rake as well as improved flame
director in the flues.
The furnace burns slowly or quickly according to the regulated position of the
different organs of it. Accordingly, I have adopted for the first case, an apparatus
adapted to distribute and regulate the air currents as may be desired, in a
rational manner under the grate; and for the second, a special brick apparatus
or construction adapted to receive an injector delivering steam or air jets under the
grate.
In order that the following specification may be clearly understood, the accom-
panying drawings have been annexed to it. In them
Figure 1 is a longitudinal section illustrating the application of the invention to
the first case, the boiler being externally fired.
Figure 2 is a combined frout elevation and a transverse section corresponding
therewith.
Figure 3 is a longitudinal section, the boiler being internally fired.
Figure 4 is a transverse section taken along the line a-b of Figure 3.
Figure 4 is a front elevation of the first flame director in Figure 3.
Figure 4B is a vertical section of the same flame director illustrating the internal
iron ring.
Figure 5 is a longitudinal section of the apparatus for the second case.
Figure 6 is a transverse section taken along the line a'-6' of Figure 5.
Figures 7 to 11 illustrate a special construction in respect of the ends of the fire
bars.
My improved furnace is characterised by all the constructional features essential
to the complete combustion of the solid fuel and the prevention of smoke from it.
Referring to Figures 1 and 2: The grate 1 of the apparatus for either of the
cases above mentioned is stopped off at the back by a hollow bridge 2 of either cast
iron or fire brick, the ends of which communicate with the side walls by the flue 3.
The back of this bridge is in one piece of refractory material hollow on the inside
and has a series of holes 4 having a diameter of from 12 to 15 mm. on the outside
and of from 20 to 25 mm. on the inside as opening. Their number is proportionate
to the size and the width of the furnace.
There is the ordinary cast iron dead plate 5 between the grate 1 and the furnace
door. 6 is the front plate of the furnace and to which the furnace and ash pit doors
aud the like are made fast.
The side walls of the furnace are built of fire lumps of a special form, which are
placed simply one on the other and the joints filled with cement. These blocks fit
into one another by tenons which fit into corresponding mortices. These latter
may have two, three or four faces.

page_text: These blocks thus joined form a solid mass and support each other. This work
is done rapidly and cleanly and is very simple. It is only necessary to place the
blocks, according to the pre-arranged position. For instance, block 7 forms the
base on it is set the perforated lump 8, and on that, the arched lump 9.
As to
the upper part 10, it may be of masonry, or of several blocks, one on top of the
other, according to the height, and the splay to be given, in relation to the
dimensions and arrangement of the furnace, see Figure 2.
In the block 7 there is a flue 11 parallel to the grate and which communicates
with the first bridge by the flue 3. The flue 11 communicates with the external
air a cast-iron pipe 12. This air supply can also be arranged in the neigh-
bouring masonry by means of an elbow bend combined with the pipe 12. Such
communication with the external air is established, or completely, or partially
arrested by the small damper 13 at the end of the said pipe. The perforated
lump 8 closes the second flue 14 formed by the hollow which is left by the arched
lump 9 taking its place on the block 7. The draught takes place in the same way
as for flue 11 and is regulated in the same way by pipes 12 and dampers 13. The
air entering by the flue 14 passes into the furnace by the numerous holes in the
perforated lumps 8.
According to Figure 2, the side walls create a combustion chamber ou each side
of the furnace, from 15 to 20 cm. above the grate. By opening the small
registers 13 and 13 of the flues 11 and 14, the exterual air is admitted to the first
bridge and the lateral combustion chambers and two currents of hot air on to the
grate, one by the bridge 2 and the other by the perforated lumps 8. This air is
divided into small jets by the numerous perforatious. The two currents of air are
directed by the special form of the bridge 15, and of the lumps 7 and 9.
The one
entering between the two bridges 2 and 15 is directed in a direction contrary to
that of the draught, by the bridge 15, and the other current coming in by the
numerous holes, in the perforated lumps 8 is directed perpendicularly to the draught
by the projections of the blocks 7 and 9. Thus whirls and eddies are produced
which ensure the mixture of the gases.
The space between the two bridges should be provided with means for being
easily cleaned. This cleansing is done simply by means of the cast-iron receiver 16
placed between the two bridges 2 and 15. It is only necessary to open the
register 17 at the proper time, for the substances deposited there to fall into the ash
pit, to be removed therefrom in the usual way.
In existing furnaces, the air necessary for combustion passes through the ash-pit
which is most of the time quite open. In my furnace it is rationally distributed
by the following means.
The space between the bottom of the fire bars and the ground, is divided into
two parts 18 and 19. In the first part 18, are arranged a series of plates in louvre
or Venetian-blind form, turning on their longitudinal axes -y, Figure 2, and
jointed at 20 to the ends of the rods 21 which are joined to a rod 22 turning in
bearings with this rod 22 in any given position, the louvres are parallel to one
another; thus forming a sort of ports through which the air reaches all parts of the
grate, as shown in Figure 1.
To produce a uniform air supply for example, in respect of the quicker
combustion obtaining at the front of the grate, and that a smaller air supply may
be delivered there, the depth of the louvres is increased progressively backwards,
in order to diminish the area of the air ports. The air regulator thus arranged
fulfils another function; namely; the regulation of the rate of combustion. In
fact, turning the rod 22, opens or closes the louvres, leaving more or less passage
for air. In this way combustion is regulated by controlling the air supply instead
of controlling the escape of the products of combustion.
When the furnace is working, the part 18 is closed by the doors 18 and the
damper which is in all furnaces, is wide open; the air regulator is arranged to
allow only sufficient air to cuter for the combustion of the coke, say about 10 kilos.
of air per kilogramme of coal burned; the additional air necessary for the

page_text: combustion of the combustible gases,-about 50% of what passes the regulator-
reaches the grate by the hollow cast iron or fire clay bridge and by the lateral
chambers, the dampers of which are arranged to suit. Consequently, hot air
comes in above and below the grate and in this way a constant stirring of the gases
is produced, as described above.
It
The grate is according to my Patents Nos. 7406183 and 77021834
possesses a large sectional area for air supply, and that allows of the bars being
placed close together. With a distance of 3 to 4 mm. between the bars, the
quantity of air reaching the fuel is more than enough to produce complete
combustion. The same narrow distance allows of the use of all fuels, especially
cheap fuel, such as small coal, dust and waste of all kinds without loss of coal in
the form of clinker. Besides, the air, being divided into many small streams,
comes easily into contact with all combustible molecules.
The grate is fitted with a special mechanism, for raking the fire mechanically.
The bearers 1 on which the grates 1 rest have on their lower parts, two projec-
tions 23, and both can be rocked to a certain extent. To facilitate this movement, the
portions of the bearers which enter the lateral walls of the furnace, do not rest
directly on the masonry but are supported on cast iron frames 24 which also serve
as guides. The rotatory movement of either extremity is produced by cams
of special form 25 fixed on axles 26 placed in the ash pit, and to which a
movement of rotation is given by a winch handle 27. The axles are supported
along the lateral walls of the ash pit by brackets 28. The rotation of the axles 26
takes place in the direction shown by the arrows in Figure 2 and the rocking of
the bearers is produced by the action of the cams 25 upon the projections 23.
When the action of the cams stops, the bearers fall by their own weight and return
to their first position. The shaking thus given to the bars causes the incombustible
materials and clinker lodged between them to fall through. It is only necessary
to give a couple of turns to each handle 27, to re-establish the air supply to the
fuel.
Instead of raking the fuel hed, by rocking the bearers at the same time on either
end and dropping them back, it is possible to raise them together, for a short
distance and parallel with each other and then drop them back. For so doing, the
two winch handles are to be used together by any suitable device. As the bars
might be displaced on their bearers, hy being jerked or jumped off the latter, I have
made the following arrangement, which is adapted to prevent such accidents. It
is illustrated in Figures 7 to 11. The ends of the bars fill up the intermediate
spaces between them-that is to say, the en 1s or heels of the bars are thicker than
the rest of the same. On one lateral face of each end or heel, there is a longitudinal
mortice p of a depth according to circumstances, from 8 mm. to 12 mm. and rounded
to allow for expansion. On the opposite face of the bar heels there is a corre-
sponding tenon o varying, from 6 min. to 10 mm. in thickness. The tenons of
one bar fitting into the longitudinal mortices p of the next bar keep the bars steady
and avoid mutual vertical displacements of the same. To prevent mutual
longitudinal displacements of the bars they are fitted at one end or heel only with
vertical tenons and corresponding mortices The combination of longitudinal
tenons and mortices on the two heels of each bar, and of vertical tenons and
mortices on one heel only prevents all accidental displacements of the bars in
vertical direction, as well as in longitudinal, but it allows for the various degrees
of expansion of the bars.
All the bars of a grate being thus regularly matched it becomes impossible to
displace them without moving the whole grate, they are arranged in groups of
3, 4 or 5 bars and between each two groups, an unmatched or plain bar is
introduced which being thus tree can be lifted easily if necessary.
Figures 3 and 4. For internally fired furnaces of cylindrical boilers, I have
adopted, in order to apply the same principle, an arrangement of fire blocks fixed
in the following manner. In the inner flue 29, there are ranged a series of fire clay
blocks 30, 31, 32, 33, of a special form fitting into one another. To give more

page_text: solidity to these superimposed blocks they are held up to the flue shell by a double
jointing 34. These blocks are perforated in order to permit the heated gises to
reach the shell of the flue so as to keep the entire surface thereof under the
influence of direct heat. These blocks only reach down to the level of the
grate on which they rest on cast iron bars fixed on the bearers 35. The grate 36
is also terminated at the back by two bridges, both built with blocks of fire clay
and having a special shape. The first bridge is built of two blocks, one over the
other and is separated from the second bridge by a small space composed of
three blocks 38, 39 and 40, which provide an internal Hue for atmospheric air
brought by the flues 41 in the side walls. Air passes into the furnace by the
openings formed in the block 38. The two bridges are laid on a
plate 42 furnished with two ports corresponding to the flue of the second
bridge and to the space separating the two bridges.
These ports are fitted with a damper 43 and are intended to provide for the
removal of cinders which are carried along by the dranght and dropped there.
Underneath, there is a cast iron case 44 closed by a door 45. The front of the grate
stops at the dead plate 46. 47 is the boiler front with the furnace door 48, the
opening to the ash pit and the cast-iron tubes 49 which connect the flues 41 with
the external air. These tubes may also, by the use of two elbow bends be extended
to the opening to the ash pit and pass into the flues 41 by an opening made in the
castings on which stand the fire blocks. These tubes are closed by dampers 50
which are fitted with hand grips.
In order to produce complete combustion, the sides of the furnace should be of
the same temperature as the burning fuel. In internally fired furnaces, combustion
is not good. It is incomplete for the reason that the temperature cannot be kept
high enough on account of the cooling produced by the metallic sides in contact
with water and the want of radiating surfaces.
As it was impossible for me in this kind of furnace to modify the walls of the
furnace by special arches, I was obliged to make an arrangement of bricks or fire
blocks in order to obtain the same radiating surface as in externally fired furnaces
to raise and maintain a high temperature in the fire box. I have always respected
the principle established by the boiler maker, in allowing the hot gases to reach
the metal walls, to retain in great measure the direct heating. I have discarded
lateral air supplies through the fire blocks on the two sides of the grate considering
it dangerous to bring highly hentel fire blocks into immediate contact with
relatively cold air. The volume of combustible gases is, moreover, less important
in this kind of furnace, and the quantity of additional air coming from the second
bridge, is here fully sufficient to complete the combustion. As at all times there
is production, and escape of either carburetted hydrogen or carbonic oxide, a
corresponding provision of air is always useful and it must be distinct from that
which enters by the grate.
By the arrangement of the bridge and its special form, the air passes through
a number of holes of very small size, that is to say, in thin jets, thus facilitating,
an easy mixture with the combustible gases and in the desired proportions
necessary to complete combustion. Thus are realized the two conditions essential
to good combustion, high temperature and contact of the gases, both combustible
and aids to combustion. For this kind of furnace, I have made another arrange-
ment of the air distributing apparatus.
The plate 51 rests on the shell 29 adapting itself to the cylindrical form of the
ash pit. It receives the louvre plates by the axles 52 which enter the holes 53.
This plate 51 is inclined-more or less according to the width of the furnace
plate, on a second horizontal bed plate furnished at the middle of the front end
with a roller 55, and at the rear with two rollers 54 for greater convenience in
fixing, and to facilitate the removal of the apparatus at the time of cleaning the
ash pit. The plates of the louvres are moveable around their axes, see
Figure 4, and connected by a link at 57 to a common rod 58 manipulated by
means of a pin 59 or otherwise, see Figures 3 and 4. This arrangement cau als

page_text: be fixed on two inclined bed-plates parallel with the sides of the ash pit, hy
fastening them on two pieces of cast iron or two horizontal iran bir furnishet at
both ends with a roller, at the front part and behind, on a transverse piece joine
to the horizontal bed plates by two vertical supports. These bed plates are
separated by two cross bars one at each end and all the parts heing bolted together,
they form a triangle.,
This last mentioned apparatus constructed in either way could be easily placed
in all furnaces without entailing any reconstruction. It is only necessary that the
dimensions and form of the construction be proportioned to the opening of the ash
pit and with the portion of the plate in front of the ash pit.
It still appears useful in certain furnaces to replace the particularly formed
upper blocks 31 and 32 by a vaulting masonry of perforated bricks. At the front
end of the furnace, the refractory blocks 30, 31, 32 and 33 are protected by a ca-t
iron plate of a like semi-circular shape to prevent their being damaged by shovel,
rake or poker.
For internally fired boilers I have adopted a form of flame lirector suitable for
these boilers.
Figures 4 and 4". By means of a series of fire blocks of special form, I
produce a ring of which about half of the surface is closed. The fixing of this is
effected in the following manner :--
After the two component parts 61, 62, of the ring 60, have been joined by their
holding screws 64, it is fixed to the shell by the same screws, and the transverse
bar 63 placed loosely upon the brackets 65.1
This ring being fixed, there are placed in position the blocks 66, 67, 68, 69,
which fit one another at both ends above and below, enveloping the iron ring 60
which is intended to support these blocks as iudicated in Figure 4. These flame
directors (of which the first is one diameter distant from the bridge, and the second
one, a radius distant) are placed so that sometimes the full part is above and
sometimes the concave part, according to the position they take to make the flame
director which alters the direction of the flame. The number of these flame
directing rings is regulated by the size of the furnace.
For artificial draught and to produce more active forced combustion, the air
distributor and regulator is replaced by the following apparatus:-
As shown by Figures 5 and 6, this apparatus is cumposel of four pieces of cast
iron 70 which are held together by tongues 71 entering grooves 72. Each piece
is furnished at one side edge with a tongue 71 and at the other side edge is the
groove 72. These pieces grouped in the ash pit, rest by their upper part, on
the walls of the ash pit and in the respective positions that they are to occupy in
the ash pit. In the case of a permanent installation, T pieces in east or wrought
iron, may be introduced on the flat into the masonry of the ash pit. They may be
hooked on to pieces 70 at the upper part bent for the purpose, and rest by the
lower part on the cast iron bearers 73.
The front part, which is shorter to allow the truck 74 to pass, receives at
opening 75, the mouth or blast pipe of an air or steam injector; and the back part
with the two sides are continned to the said truck 74 which receives the cinders
which fall through the grate. The size of the truck is proportioned to the grate
or the ash pit; but its capacity, (while never more than one third that of the ash
pit) is quite sufficient; considering that with bars only 2 mm. apart, adapted for
this furnace, fiue ashes well consumed, can alone fall through the grate. The
quantity of cinders is therefore limited. Moreover, the truck can be easily
emptied as often as required running as it does on rollers fitted to rails.
When the size of the front of the ash pit permits, the apparatus can also be
placed on a car which may be run into the ash pit. For the iron or cast iron
apparatus, a brick structure can he substituted.
When the grate is very long, the ash pit is to be divided in two parts, of the
same length. Instead of one apparatus, two similar ones are used. They are fed
separately by an injector. The construction of the sides of the furnace remains.

page_text: the same as shewn in Figures 1 and 2; the perforated lumps 8 may however be
replaced by plain lumps of the same shape or the arched lumps 9 may be directly
on the blocks 7 without leaving an internal hollow, supposing the side air draughts
be dispensed with.
The grate 1 the surface of which is less than that of the grate 1 before described
is stopped off at the back by the second bridge properly called 15, the first hollow
bridge 2, see Figures 1 and 2, being also dispensed with.
The flue 11 of the interior blocks 7 is prolonged beyond the bridge 15-see
Figures 2, 5 and 6.
At some distance behind the bridge 15, there is masonry 76 of the same height
and the same level. It has a thickness of one brick or of half a brick according
to the size of the furnace. Equidistant from the bridge 15 and this masonry 76 is
an arch 77 with its top against the crown of the flue; the lower part of this arch
reaches down to the level of the bridge 15; and again at an equal distance behind
this first arch there is a second arch 78 like the first, but whose lower portion is
lower than the level of the first arch 77.
The number of these arches may be doubled or trebled according to need.
These two arches 77 and 78 and the masonry 76 behind the bridge serve to stop
the flame and to force it to take another direction. I have therefore called them
"flame directors."
Thus, I produce a series of combustion-chambers I, II, III, behind the bridge,
in the first flue, limited to three chambers for this arrangement.
The flue 11, passing across the bridge 15, reaches as far as the first upper flame
director and communicates with the hollow interior 79 of the flame director 77,
whose back wall is perforated.
For larger furnaces and according to the nature of the coal in respect of its
volatile constituents, the flue 11 is enlarged and divided into two compartments 11
and 11. One of these cominunicates with fine 79 of the flame director 77, and
the other with the Hue 80 of the flame director 78. The air can also be made to
enter along flues 79 and 80 by a flue made in the lateral masonry and com-
municating directly with the flame directors 77 and 78. The flue 11 is thus
connected by one of its ends with the flue 79, and 80 if there is room; and the
combustion chamber 11, by the exit holes in the back of the flame director 77, and
also 78 if there is room.
The combustion chambers I and III receive in great part the ashes carried along
by the draught and which are precipitated by the sudden stoppage produced by
the flame directors 77 and 78. It is therefore necessary that they should be
removed easily. For this purpose, the chambers in question are closed by the
plates of the movable louvres turning on the axis, see Figure 5.
The moveable louvres are connected to the rod 81 by links which pass into the
masonry and are worked by the hand from the outside.
These chambers can thus be cleaned at will during the work, the ashes falling
into a large space reserved behind the ashpit with which it communicates by the
opening 82 which is usually closed.
Here then are the advantages of the combination of constructions and of the
various apparatus having each its own special function within its sphere of action,
all of which unite to render my improved furnace economical and smoke-
consuming.
The usual way of supplying air to the underside of the grate through the ashpit
as it exists, is defective for the following reasons.
As the back of the grate is in the most direct road for the air drawn by the
chimney, the combustion is most advanced there, the air meeting the least
resistance to its course. The temperature there is also higher than in other parts
of the ashpit, all which circumstances tend to draw the air chiefly to the back of
the grate.
The ashpit being completely open accentuates this disadvantage.
There is, therefore, an excess of air supply to the back of the grate, the remainder

page_text: of it, especially the front, having an insufficient supply, two grave hindrances to
the best utilization of the fuel.
My apparatus for distributing the air rationally un ler the grate gets rid of these
hindrances. All parts of the grate are supplied regularly and in such a way that
each one receives the right quantity, in proportion to the combustion required
there. The air supply is also previously heated by the plates of the louvres.
The distributing apparatus is also a more rational regulator and more convenient
than the chimney damper. The activity of combustion should be regulated by the
air supply to the underside of the grate and not by the escape of the products of
combustion. Closing the damper more or less, checks combustion by keeping the
gases longer in the flues and that is often injurious to the iron plates.
The air distributed by the distributor is uniformly spread through all the mass
of fuel by the grate, whose many openings divide the said air into a number of
thin streams. This ensures the contact of the combustible molecules with the
supporter of combustion; and by the air supplies from the side walls and from the
bridge above the grate, I establish a mixing and churning necessary for the chemical
combination of the gases. Further, whether the air comes from below or from
above it is hot when it reaches the grate and the furnace, by reason of it having
passed through the distributor and the flues.
The bars of the grate are sufficiently close to prevent any loss of fuel in the
form of cinders, through them even with the smallest coal.
On the other hand the mechanical raking of the bars obviates the necessity of
frequently opening the doors and the grate is never choked.
By the side chambers parallel to the grate and the arches of the lateral walls
and of the second bridge, I remedy also a fault in existing furnaces.
To obtain complete combustion in so large a space as that occupied by a boiler
furnace, one must not only have the necessary volume of air but also a sufficiently
high temperature, to produce combustion of the hydrocarbons, and as the volume
of gas increases in proportion with the rise in temperature; it is absolutely
necessary that the cavity of the furnace should be proportionate to the volume of
gases.
In existing furnaces, the width is the same as the grate and often even less on
account of masonry at the sides, so that the gases are contained in a too limited
space and are carried away by the too rapid draught. The time necessary for
chemical combination is therefore altogether too limited, and this is one of the
principal reasons of the inferior utilization of fuel in industrial furnaces.
By the side chambers of my improved furnace, the gases find a space propor-
tionate to their volume, which increases the time they are in the furnace, and by
the intense radiation of the heat retaining fire-clay arch, the temperature of the
furnace is raised permanently and by the air supply above the grate, all the
conditions necessary for complete combustion are united.
As the great consumption of fuel and the rapid work demanded at the present
time, render it desirable that inferior fuel should be utilized, and that the
evaporating power of the boilers be increased as may from time to time be
required, I have also arranged my furnace to allow of forced draught by means
of a blower or fan.
All the furnaces furnished with a fan which have been tried have failed
practically on account of the following disadvantages:
1st. Too great expenditure of steam.
2nd. The great danger of generating explosive gases by jets of air or steam
which may burn the iron plates.
3rd. The deposit of a mass of cinders in the flues which become obstructed by
them in a short time, whereby a large part of heating surface is lost.
These disadvantages proceed largely from the fact that in present furnaces, a
fan is used which is not suited to the mode of henting employed.
Instead of blowing steam or compressed air into a space so large as that occupied

page_text: by the ashpits of existing boiler furnaces, which requires great pressure, and causes
great waste of steam, or an important waste of power used to produce the useful
effect of compressed air, the mouth of the blast pipe of an air or steam injector
opens in an envelope of iron, cast iron or even of bricks. The conical form of
this envelope correspon.ls in the wide part with the length of the grate. Thus
with low pressure I obtain good result, and a greater depression by a more regular
distribution of air through the mass of combustible matter.
In applying this method of heating to my furnace, I diminish the surface of the
grate by one third, but I retain the same space in the side combustion chambers,
on account of the activity given to the combustion which increases noticeably the
volume of gas in the same period of time. In this way, the gases find the space
which is necessary to them and their period of retention in the furnace is
prolonged.
The jets which produce the effect of jets of explosive gas, are caused by excessive
pressure which is set up especially when the grate is choked or under charged.
With the mechanical raking and my rocking apparatus the grate is never choked,
and with my system of bars very closely laid with numerous openings, the uniform
distribution of air is always a necessary consequence.
With a smaller grate surface, the stoker could also better extend the fuel over
the whole extent of it, and the charges of fuel must be greater.
The entrance of einders into the flues is avoided by the flame directors behind
the bridge. The flame striking these directors is subjected to detention, during
which, before taking another direction, the ashes are deposited in the chambers
which separate the various flame directors from one another, whence they are
easily removed (without interrupting the work), by the rotation of the louvre plates
which close them in.
These chambers have yet another end in view. By the whirls and movements
produced in changing direction, the rapid current of gases is reduced in speel, and
their contact with the receiver is prolonged. The churning which ensues is
eminently favorable to an intimate mixture of the combustion supporting and the
combustible gases, and as there are air supplies to the upper chambers which can
never be obstructed by cinders, all the conditions necessary to produce complete
combustion and best utilization of the heat are united.
By giving a small surface to the grate with greater height still to the furnace,
and by placing flame directors 77 and 78 in communication with the external air
by the side flues and by making application of the two bridges-Figs. 1 and 2-
with an air supply, by the flue 11, in the first bridge 2, this furnace should become
a veritable gas producer.
Applied to heating by slow combustion or for forced draught my furnace is
economical and smoke consuming.
It must be understood that the present invention includes the application of
either of the above described apparatus to any existing furnace or to any new
construction.
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. The apparatus for the rational distribution of the air supply to the under side
of the grate applicable to any furnace, by a suitable arrangement, and the special
apparatus for producing it, consisting of a series of louvres moveable on a horizontal
axis and jointed at the ends of the rods which are connected with an axis either
horizontal, vertical or inclined; an apparatus which allows also of the regulation
of the rate of combustion, by acting on the admission of air instead of acting on
the escape of the products of combustion,
2. The side combustion chambers allowing of the increase of space above the
grate and of the entrance on to the grate and above the fuel bed of air already
heated during its passage.

page_text: 3. The arched side walls, built of blocks of fire-clay of a special shape, placed
one above the other, fitting into one another by flanges entering grooves made for
the purpose and furnished internally with flues for circulation of air, opening into
the furnace through holes in a perforated brick specially prepared; the blocks
being also provided with angles to force the hot air coming from the side flues to
infringe on the grate more or less perpendicularly to the draught, causing whirls
and movements producing perfect mingling of gases, and the storage of a great
quantity of heat adapted to maintain by radiation the high temperature of the
furnace.
4. The two bridges of equal or different height placed at a certain distance
apart, the first permitting the entrance of hot air by the side flues to the fuel, the
two bridges forming besides a combustion chamber in the furnace itself, and the
form of the bridge properly so called, obliging the hot air coming from the first
bridge to pass to the front of the grate, that is to say, contrary to the direction
of the draught, so as to produce whirls and disturbances for the mixture of
the gases.
5. An internally fired furnace provided with sides in brick with the object of
creating a radiating surface for raising the temperature of the furnace, and the
special shape, given to these blocks of perforated fire-clay with a view of fixing
and joining them together without any other masonry than a little cement for the
joints, and their position as removed from the plates of the flue.
6. The apparatus for mechanically raking, based on a series of movements or
shocks repeatedly given to the grate, as set forth and illustrated.
7. The system by which the ends of the bars are fitted, as described and
illustrated in Figures 7 to 11.
8. An apparatus, or arrangement of masonry, in every ash pit to receive the
mouth of a blower or ventilator or the blast pipe of a steam injector, and the form
and the construction adopted for this apparatus or for the masonry, as described
and illustrated.
9. The series of flaine directors, fixed at a certain distance behind the bridge
and distant from one another by a space in proportion to the size of the furnace,
as described and represented, with a view to delaying the flame and the gaseous
current and to change their direction, thereby providing for the deposition of ashes
brought by the draught, and the whirls and disturbanee favourable to perfect
mixture of combustion supporting and combustible gases.
10. The air supply by side flues in the fire blocks or the lateral masonry, and the
special shape of the perforated bricks to obtain fine streams or jets, offering a
large surface of contact for the combustible gases.
11. The combustion chambers behind the bridge formed by the flame directors,
and from which the lower chambers receive the cinders carried by the draught,
and the system of closing these chambers by moveable louvres working on an axis
to allow removal of the cinders without interruption of the work, by means of a
rod passing through the masonry and worked by hand from the outside.
12. The flame directors in the first ring, applied to internal furnaces and the
form and construction of the flame directors by superposed and fitting blocks with
flanges and grooves connecting them closely, also the method of fixing these blocks
to the walls of the boiler flue by a ring of iron, or by a transverse block of fire-clay
fixing the side Llocks against the flue."
13. The general construction of improved furnace, as set forth.
All as above described, and represented in the accompanying drawings.
PHILLIPS & LEIGH,
No. 22 Southamptou Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.