Improvements in and relating to Furnaces.
Year: 1894

page_text: Date of Application, 6th Mar., 1894.
Complete Specification Left, 6th Dec., 1894-Accepted, 12th Jan., 1895
[Communicated from abroad by EMILE JOLICARD, of Lyon, in the Republic of
France, Engineer.]
Improvements in and relating to Furnaces.
I, HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, do hereby declare
the nature of this invention to be as follows:-
This invention relates to an improved arrangement of furnace for pulverized
fuel, which is applicable to boilers and generators or may also be used for industrial
purposes.
The improved furnace for pulverized fuel is substantially composed of the
following parts, that is to say a lighting chamber for wood charcoal, wherein a
current of air and pulverized coal arrives through an inlet pipe; a vertical furnace
portion wherein are arranged in crossed rows, separated by a small space, horizontal
round columns leaving a small space between them; a horizontal furnace portion
provided with other round columns placed at short distances from each other in all
directions; combustion chambers for the gases provided behind the furnace proper
and limited by walls pierced with vertical slits or openings.
This furnace may consist of refractory earth and be built upon a vault bearing
upon the boiler.
The operation of this improved furnace is as follows:-
In the case of a single furnace the current of cold air and pulverized coal
arriving through the inlet pipe is obliged to pass downwards through the incan-
descent wood charcoal, thus determining the ignition of the fluid vein. The latter
then passes still downwards through the rows of bricks or columns, utilizing the
passages open to it and the free space provided between two horizontal rows of
these bricks or columns, thus creating an enlargement of section and causing
whirling movements greatly favourable to the ignition of the gases.
. The wood charcoal burns while the whole of the columns and of the furnace
gradually reaches a higher temperature, and when the wood charcoal bas dis-
appeared, the furnace, by its refractory material raised to a high temperature and
presenting a large surface of contact to the gases, retains a considerable amount of
heat which serves to ignite the current of air and coal dust which are continually
renewed therein.
This furnace may comprise either a vertical part only, or a horizontal part only,
or a vertical and horizontal part combined.
•
At the outlet of the furnace one or more chambers are provided for the com-
bustion of the gases. In these chambers the gases already ignited react one upon
the other and complete their combustion. Walls having either straight slits a single
opening serve to diffuse the burning gases and are always heated to incandescence
during the operation.
In case the inlet pipe has to feed several furnaces use is made of a special
arrangement enabling the distribution of the vein of air and coal to be effected
into as many branch pipes as may be necessary for feeding the furnaces.
Each of the branch pipes should have a sectional area proportional to the quantity
of coal which is to be Lurnt by the furnace. In a series of furnaces, such as for:

page_text: example boiler furnaces, all the elements are generally equal, that is to say each of
the furnaces burns as much as the neighbouring furnace; so that all the branch
pipes will have the same sectional area.
For instance in the case of four furnaces the four branch pipes are preferably
curved and have each a sectional area equal to one-fourth of the sectional area of
the main pipe. At the points where these branch pipes leave the main pipe a
truncated cone is provided in the latter, which cone has approximately the length
of the greatest diameter of the oblique section of this branch. The parts of the
main pipe which follow these truncated cones have each a smaller sectional area
than the preceding by one quarter of the principal sectional area, that is to say the
first part has three quarters of a sectional area of the main part, the second part
one half of the sectional area of the main part, while the third part has only one
quarter of the sectional area of the said main part.
In each branch pipe is included a valve enabling one or more of the furnaces to
be completely shut off and each furnace to be regulated to the same pressure.
Dated this 6th day of March 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
I, HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co., Patent
Agents, 45 Southampton Buildings in the County of Middlesex, 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 an improved arrangement of furnace for pulverized
fuel, which is applicable to boilers and gas generators or which may also be used
for industrial purposes.
In the accompanying drawing,
Figure 1 represents a central longitudinal section of a furnace constructed
according to my invention.
Figure 2 shows a partial section on the line 1-2 of Fig. 1 taken through the
part situated on the left of its axis and a section on the line 7-8 of the same
figure taken through the other part situated on the right of the axis.
Figure 3 represents in plan a section on line 3-4 of Fig. 1.
Figure 4 is a plan showing a section on the line 5 6 of Fig. 2 and
Figure 5 shows the arrangement used when a series of furnaces are all fed by a
single main pipe.
The improved furnace for pulverized fuel is substantially composed of the
following parts:-A lighting chamber M for wood charcoal, wherein a current of
air and pulverized coal arrives through the inlet pipe C.
A vertical furnace portion A wherein are arranged in crossed rows, separated
by a small space, horizontal round columns E leaving a small space between
them.
A horizontal furnace portion B, the longitudinal section of which is represented
in Figure 1 and the horizontal section in Figure 3, which figures show other round
columns F placed at short distances from each other in all directions and arranged
in this part of the furnace. Combustion chambers L for the gases, provided behind
the furnace proper and limited by walls K K pierced with vertical slits or openings
as shown in Figures 1 and 2.
This furnace may consist of refractory earth and be built upon a vault G bearing
upon the boiler.

page_text: The operation of this improved furnace is as follows :—
In the case of a single furnace the current of cold air and pulverized coal
arriving through the inlet pipe C is obliged to pass downwards through the incan-
descent wood charc al, thus determining the ignition of the same. The latter then-
passes still downwards through the rows of bricks or columns, utilizing the passages
open to it and the free space provided between two horizontal rows of these bricks
or columns, thus creating an enlargement of section and causing whirling movements
very favourable to the ignition of the gases.
The wood charcoal burns while the whole of the columns and of the furnace
gradually reaches a higher temperature, and when the wood charcoal has dis-
appeared the furnace, by its réfractory material raised to a high temperature and
presenting a large surface of contact to the gases, retains a considerable amount of
heat which serves to ignite the current of air and coal dust which are continually
renewed therein.
This furnace may comprise either a vertical part only, such as A, or a horizontal
part only, such as B, or a vertical and horizontal part combined as represented in
the drawing.
At the outlet of the furnace one or more chambers L are provided for the
combustion of the gases. In these chambers the gases already ignited react one
upon the other and complete their combustion. Walls K having either straight
slits, as represented in vertical section on the right hand side of Figure 2, or a
simple opening serving to diffuse the burning gases and are always heated to
incandescence during the operation.
In case the inlet pipe has to feed several furnaces use is made of a special
arrangement enabling the distribution of the current of air and coal to be effected
into as many branch pipes as may be necessary for feeding the furnaces.
Each of the branch pipes should have a sectional area proportional to the
quantity of coal which is to be burnt by the furnace. In a series of furnaces, such
as for example boiler furnaces, all the elements are generally equal, that is to say
each of the furnaces burns as much as the neighbouring furnace, so that all the
branch pipes will have the same sectional area.
In Figure 5 of the drawing we have represented only four furnaces.
In this case the four branch pipes c c c² are preferably curved and have each
a sectional area equal to one-fourth of the sectional area of the main pipe C. At
the points where these branch pipes leave the main pipe truncated cones D D' D'
are provided in the latter, which cones have approximately the same length as the
greatest diameter of the oblique section of this branch. The parts C¹ C³ C³ of the
main pipe C which follow these truncated cones D D'D' have each a smaller sectional
area than the preceding by one quarter of the principal sectional area, that is to
say Chas three quarters of a sectional area of C while C has one half of the
sectional area of C, and C³ only one quarter of the sectional area of C.
C
In each branch pipe cc cc is included a valve enabling one or more of the
furnaces to be completely shut off and each furnace to be regulated to the same.
pressure.
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 :-
:-
First. A lighting apparatus for furnaces burning pulverized fuel by means of a
reverse flame, use being made of a light coal adapted to undergo complete com-
bustion under the action of a strong current of air and pulverized coal for which
purpose wood charcoal is generally employed.
Second. A furnace for pulverized fuel, with passages of small sectional area,
the fluid current moving at a great velocity, which furnace is constituted by piles
or columns of round, elliptical, polygonal or other section, arranged in rows and
separated from each other so as to present enlarged parts behind narrow sections of
the passage for the purpose of diminishing the velocity of the said fluid current,

page_text: causing all the parts to communicate frequently with each other, dividing the
principal current into a great number of others, and thus obtaining a great surface
of contact between the air and pulverized coal and the material of the furnace thus
constructed, which serves to retain the heat during the operation.
Third. In furnaces for pulverized fuel the combination of the lighting apparatus
and furnace proper with one or more combustion chambers for the gases at the
outlet of the said furnace substantially as and for the purpose set forth.
Fourth. In furnaces for pulverized fuel the combination of the devices herein-
before described with straight passages adapted to be easily cleaned, substantially
as represented in Figures 3 and 4 of the accompanying drawing.
Fifth. In furnaces for pulverized fuel the arrangement of the pipes with
successive contractions enabling a number of furnaces to be fed substantially
as hereinbefore described and represented in Figure 5 of the accompanying
drawing.
Dated this 6th day of December 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.