Improvements relating to the Smokeless Combustion of Fuel, and to Apparatus for Effecting such Combustion.
Year: 1892

page_text: Date of Application, 16th Dec., 1892
Complete Specification Left. 8th Sept., 1893-Accepted, 14th Oct., 1893
PROVISIONAL SPECIFICATION.
[Communicated from abroad by EUGEN CLARENBACH, of 18, Wilhelm Strasse,
Berlin, in the Empire of Germany, Engineer.]
Improvements relating to the Smokeless Combustion of Fuel, and to
Apparatus for Effecting such Combustion.
I HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co. Patent Agents
45 Southampton Buildings London, in the County of Middlesex, do hereby declare
the nature of this invention to be as follows:-
This invention relates to the smokeless combustion of fuel and to apparatus for
effecting such combustion.
It is more particularly applicable to furnaces in which
the fuel is filled into a shaft or chute to which the combustion chamber on the
furnace joins below.
According to the aforesaid invention the air for the combustion, introduced at
the upper end of the chute in quantities which may be regulated, is conducted on
its way to the furnace below along the periphery of the column of fuel through a
space which may or may not be divided into two or more compartments. The
peripheral space opens at the top into the part of the chute which is designed for
introduction of the fuel, and at the bottom into the furnace. Through slots or
channels it is moreover in communication with the interior of the chute containing
the fuel, so that the air has access to the same; on the other hand the gases from
the fuel can pass to the peripheral space.
By the action of the chimney draught upon the air for the combustion conducted
along the periphery of the column of fuel is effected the mixing of the gases from
the coal, which pass outwards into the peripheral space, with the air, and this
combustible mixture, which comes in contact with hot surfaces of gradually
increasing intensity, is conveyed in the most direct manner into the furnace.
As on the other hand part of the air in its downward movement passes through
the slots or channels from the aforesaid single or divided peripheral space into the
chute it causes at the periphery of the column of fuel a combustion which increases
in intensity as the distance to the furnace diminishes.
By this means and in consequence of the gradual increase of the dry distillation
in the column of fuel towards the fire, a certain increase of temperature of the air
and also of the gases from the coal or of the combustible mixture formed by the
air and gases takes place, thereby ensuring a very perfect combustion with forma-
tion of a white flame.
The constitution of the annular peripheral space of the chute depends upon the
special object of the furnace to which the invention is to be applied. With furnaces
in which a comparatively small developement of heat takes place, such as those for
stoves designed for heating rooms, the chute may be formed of a metallic cylinder
with longitudinal slots or holes and arranged concentrically in a wider casing which
terminates above in the space where the fuel is introduced and opens below towards
the furnace. In the case of furnaces for generating more heat, a kind of basket
grate constituted by longitudinal bars, or a tube provided with numerous lateral
channels and made of refractory materials, may be substituted for the above-
mentioned metallic cylinder.
If the improved method is to be applied to the furnace of a steam boiler with
internal flues the chute provided according to this invention either with a single or
a divided peripheral space may terminate in the furnace at a point situated above
the grate. The products of combustion generated, starting from the furnace will

page_text: then take their usual course in order to circulate round the heating surface of the
boiler and to pass finally into the chimney.
Dated this 16th day of December 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to the Smokeless Combustion of Fuel, and to
Apparatus for Effecting such Combustion.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, London, 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 :-
This invention relates to the smokeless combustion of fuel and to apparatus for
effecting such combustion. It is more particularly applicable to furnaces in which
the fuel is filled into a shaft or chute to which the combustion chamber of the
furnace joins below.
According to the aforesaid invention the air for the combustion, introduced at
the upper end of the chute in quantities which may be regulated, is conducted on
its way to the furnace below along the periphery of the column of fuel through a
surrounding space which may or may not be divided into two or more compart-
ments. The said surrounding or peripheral space opens at its upper end into that
part of the chute which is designed for introduction of the fuel, and at the bottom end
into the furnace. Through slots or channels it is moreover in communication with
the interior of the chute containing the fuel, so that the air has access to the same,
on the other hand, the gases from the fuel can pass to the peripheral space or
spaces.
Now by the action of the chimney draught upon the air for the combustion
conducted along the periphery of the column of fuel is effected the mixing of the
gases from the coal or other like fuel, which pass outwards into the peripheral
space, with the air, and this combustible mixture, which comes in contact with hot
surfaces of gradually increasing intensity, is conveyed in the most direct manner
into the furnace.
As on the other hand part of the air in its downward movement passes through
the slots or channels from the aforesaid single or divided peripheral space into the
chute, it causes at the periphery of the column of fuel a combustion which increases
in intensity as the distance to the furnace diminishes.
By this means and in consequence of the gradual increase of the dry distillation
in the column of fuel towards the fire, a certain increase of temperature of the
air and also of the gases from the coal or of the combustible mixture formed by
the air and gases takes place, thereby ensuring a very perfect combustion with
formation of a white flame.
In order to state more clearly how this invention is carried into effect, we shall
now proceed to describe, as an example, a furnace to which it is applied. For this
purpose a steam boiler known as Cornish boiler provided with the means mentioned
above for effecting a smokeless combustion is represented on the annexed sheet of
drawing.
Fig. 1 shows in a vertical section a steam boiler with internal flues, Fig. 2 a
section following the line m n in Figure 1.
The flue e contains a fire-grate b in the usual manner, but this grate is fed with
the fuel from above, by means of a vertical chute provided with jacket 1 and
connected to the flue e just above the grate b. According to circumstances the
chute however, may also extend upwards in an oblique line.

page_text: The chute filled with the fuel through the door o consists of a cylindrical or
prismatical tube or shaft d and is arranged within the jacket / so as to leave a
free peripheral or annular space i between the chute and the jacket l. This
annular space i opens at the top into the upper part of the chute which as
well as the jacket is surmounted by a cover o while the bottom end of said
annular space i opens directly into the furnace. By means of slots or channels /
arranged in the walls of the chute d the interior of the same communicates with
the peripheral space i, the area of each of these slots or openings being so, that
no particles of fuel can fall or be pressed into the peripheral space i. Projections 9
of the tube d, reaching almost to the inner surface of the jacket 1 secure the tube
on its place within said jacket. The projections g at the same time may serve as
means by which the tube d rests upon a peripheral edge k projecting inwards
from the jacket l.
The cover or door o for closing the chute is provided with an opening to enable
the access of air for the combustion and this opening is preferably provided
with a damper or slide a' for regulating the quantity of air drawn in by the
chimney. This air in part enters directly into the peripheral space i and partly
penetrates first the upper layers of fuel in the chute and then by the slots passes,
in the said space i, from where by the chimney draught it is drawn downwards to
the fire room or furnace above the grate b.
The communication between the space and the upper part of the chute may
also be effected by the slots or channelsh alone, in case it appears desirable, to
cover the space i by a rim or flange of the chute or shalt d, for preventing pieces
of coal to drop into the said space.
The fuel filled by the door o into the chute rests upon grates and b
The highly heated gases generated on the grate and in the lower part of the
column of fuel radiate upwards in this column and thus produce a dry distillation.
The products thereof pass by the slots over into the peripheral space i and are
drawn by the chimney draught from here directly in the fire-zone, without
penetrating the upper layers of the column of fuel.
In this way a perfect coke-burning of the fuel is ensured. The coal gases on
their way to the peripheral space i and therein downwards to the fire-zone encounter
burning layers of fuel and the hot walls of the chute d. They met with the
descending air and this mixture arrives at the fire-zone in a heated state and in a
condition which ensures a smokeless combustion.
The chute d being subjected to a great heat, is with preference formed of
refractory material. The lower part of it has in a certain sense the effect of a
grate, the result of which is, that the efficiency of the furnace increases with
the length of the slots or with the height of the column of fuel.
The products of combustion from the furnace will then take their usual course,
they circulate around the heating surface of the boiler and pass finally into the
chimney.
In order to enable the stirring of the grate and clearing of the same a door c in
the axis of the flue e is provided.
The construction of the annular peripheral space i depends upon the special
object of the furnace, to which the invention is to be applied. With furnaces in
which a comparatively small development of heat is to take place, such as those for
stoves designed for heating rooms, the chute may be formed, instead of fire-proof
brickwork or the like, of an iron cylinder with longitudinal slots or holes and
arranged concentrically in a wider casing, such as in the drawing, which
terminates above in the space a where the fuel is introduced and opens below into
the furnace.
In furnaces for generating more heat however, a kind of basket grate, constructed
of longitudinal bars, may be substituted, if desired, for the shaft d which in the
drawing is shown as being made of refractory material and provided with numerous
lateral channels.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent I declare that what I claim is:
1. The improved method or process of producing a smokeless combustion of fuel,
which consists in introducing the air for the combustion at the upper end of the
column of fuel, conducting the air on its way to the furnace below along the
periphery of the column of fuel, mixing the same on its way to the fire-zone with
products of dry distillation of the coal, subjecting this mixture of air and gas to a
high and increasing temperature, so to render it highly heated, when it reaches the
fire-pot, and finally conducting off the products of the complete combustion,
substantially as hereinbefore described.
2. In a furnace for producing a smokeless combustion of fuel, the combination
with the shaft or chute f for the fuel, of a surrounding or annular space, opening
at the top into that part of the chute which is fed with the fuel and at the bottom
into the fire-pot, and slots or channels forming communications between the air
space and the interior of the shaft or chute, essentially as described.
3. In a furnace for carrying out the aforesaid improved method of producing a
smokeless combustion of fuel, the door o provided with damper or slide a¹ for
regulating the access of air, essentially as set forth.
Dated this 8th day of September 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.