Improvements in Apparatus and Appliances for Obtaining More Perfect Combustion of Fuel in the Furnaces of Steam Generators.
Year: 1887

page_text: Date of Application, 19th Apr., 1887
Complete Left, 19th Jan., 1888
Complete Accepted, 3rd Feb., 1888
Improvements in Apparatus and Appliances for Obtaining More
Perfect Combustion of Fuel in the Furnaces of Steam Generators.
I JOSEPH PLATT, of Highfield Villa Pitsmoor, Sheffield, in the County of York,
Ironworks Manager, do hereby declare the nature of my said invention for " IMPROVE-
MENTS IN APPARATUS AND APPLIANCES FOR OBTAINING MORE PERFECT COMBUSTION OF
FUEL IN THE FURNACES OF STEAM GENERATORS," to be as follows:-
The object of my invention is to economise fuel and minimise the production of
smoke and I effect this by obtaining a more perfect combustion of fuel by means of
my improved apparatus and appliances.
Although my invention is applicable to various types of steam generators, irrespective
of the form of furnace, or methods of firing the same, a description of the apparatus as
applied to a "Cornish Steam Boiler" will suffice:
In the furnace of such a boiler I construct an air box in the fire bridge, such air box
being either formed in the brick work of the bridge, or it may be constructed of fire
clay, or of metal, faced with fire brick.
This air box is provided with an opening for admission of a pipe to the rear of the
bridge, and it is likewise provided with a cover brick, or bricks, of a particular shape,
(hereinafter described,) each brick being provided with a separate orifice connected
with the interior of the air box.
In the bottom of the bridge below the fire bars, I place a metallic or fire clay pipe,
the mouth of which comes through the front of the bridge. The pipe itself being
carried on the bottom of the flue tube for a certain distance, which will be regulated
to some extent, by the diameter and length of the flue tube, position of cross tubes
and other circumstances. The length of the bottom pipe having been fixed, its
direction is then turned back towards the bridge, where it is connected with the
opening in the air box, previously referred to. In the bottom of the flue tube under-
neath the fire bars, I place a plate or plates, so as to lay horizontally above the mouth
of the pipe in the bottom of the bridge, thus protecting it from becoming choked up
by the dust, and ashes, which fall through the fire bars.

page_text: This plate or these plates may be provided with ribs running longitudinally or
otherwise, on the under side; and the plate or plates themselves extending from the
front of the bridge to the front of the boiler forming an air space, or air spaces,
which may be provided or not, as circumstances may require, with a valve, or slide,
by which the admission of air may be regulated.
When the boiler is at work, the plate.or plates below the grate bars become heated
by the cinders and ashes which fall from the bars, and the air admitted into the space
or spaces below what may be called the ash plate, becomes heated in its passage towards
the mouth of the air pipe in the bottom of the fire bridge, and in passing through this
pipe, the air is further heated, as it approaches the air box in the fire bridge, whence
it is discharged through the orifices in the specially formed cover brick, or bricks, at
the top of the fire bridge, and in its heated and rarified condition it amalgamates with
the gases and other products, generated in the fire place, thereby contributing to
more perfect combustion and increasing the amount of flame and intensity of heat in
the Furnace.
The cover brick or bricks of a particular shape herein previously referred to;
partake of the same, or similar, form and construction, as the air bricks described in
my Patent, Number 7805, dated 26th June, 1885, and illustrated in Figs. 1, 2, 4, 5, 6
and 7 on the sheet of drawings accompanying the Complete Specification of that
Patent, which comprises a fire brick or bricks or combinations of fire bricks provided
with orifices for use on the top of the fire bridge through which orifices the heatod air
is discharged horizontally from the air box or passages in the bridge.
Although in the illustration herein given, of the application to a Cornish boiler,
one air pipe or passage only is described for conveying the air from the bottom of the
fire bridge, to the air box at the back of the fire bridge, I do not confine myself to one
pipe, as several such pipes may be used or one large lower pipe may be used in
connection with several smaller upper pipes, each of which may have a separate opening
into the air bridge, or all of which may converge into one central opening in the air
bridge.
DL: 101
SA 1007

page_text: Improvements in Apparatus and Appliances for Obtaining More
Perfect Combustion of Fuel in the Furnaces of Steam Generators.
I, JOSEPH PLATT of Highfield Villa Pitsmoor, Sheffield, in the County of York,
Ironworks Manager, do hereby declare the nature of my said invention for
"IMPROVEMENTS IN APPARATUS AND APPLIANCES FOR OBTAINING MORE PERFECT
COMBUSTION OF FUEL IN THE FURNACES OF STEAM GENERATORS," and in what manner
the same is to be performed to be particularly described and ascertained in and by
the following statement :-
The object of my invention is to economise fuel and minimise the production of
smoke, and I effect this by obtaining a more perfect combustion of fuel by means of my
improved apparatus and appliances.
Although my invention is applicable to various types of steam generators irrespective
of the form of furnace, or methods of firing the same, a description of the apparatus as
applied to a Cornish steam boiler will suffice.
In the furnace of such a boiler I construct an air box in the fire bridge, such air box
being either formed in the brick work of the bridge, or it may be constructed of fire
clay, or of metal, faced with fire brick.
This air box is provided with an opening for admission of a pipe to the rear of the
bridge, and it is likewise provided with a cover brick, or bricks, of a particular shape
(hereinafter described) each brick being provided with a separate orifice connected
with the interior of the air box.
In the bottom of the bridge below the fire bars, I place a metallic or fire clay
pipe, the mouth of which comes through the front of the bridge. The pipe itself
being carried on the bottom of the flue tube for a certain distance which will be
regulated to some extent, by the diameter and length of the flue tube, position of cross
tubes and other circumstances. The length of the bottom pipe having been fixed, its
direction is then turned back towards the bridge where it is connected with the
opening in the air box previously referred to. In the bottom of the flue tube under-
neath the fire bars, I place a plate or plates, so as to lay horizontally above the mouth
of the pipe in the bottom of the bridge, thus protecting it from becoming choked up
by the dust and ashes, which fall through the fire bars.
This plate, or these plates, may be provided with ribs running longitudinally or
otherwise on the under side; and the plate or plates themselves extending from the
front of the bridge to the front of the boiler forming an air space, or air spaces, which
may be provided, or not, as circumstances may require, with a valve or slide, by which
the admission of air may be regulated.
When the boiler is at work, the plate or plates below the grate bars become heated
by the cinders and ashes which fall from the bars, and the air admitted into the space

page_text: or spaces below what may be called the ash plate, becomes heated in its passage
towards the mouth of the air pipe in the bottom of the fire bridge, and in passing
through this pipe the air is further heated as it approaches the air box in the fire
bridge, whence it is discharged through the orifices in the specially formed cover
brick, or bricks, at the top of the fire bridge, and in its heated and rarified
condition it amalgamates with the gases and other products, generated in the fire place
thereby contributing to more perfect combustion and increasing the amount of flame
and intensity of heat in the Furnace.
The cover brick or bricks of a particular shape herein previously referred to, partake
of the same, or similar, form and construction as the air bricks described in my Patent
Number 7,805, dated, 26th June, 1885, and illustrated in Figs. 1, 2, 4, 5, 6, and 7 on
the sheet of drawings accompanying the Complete Specification of that Patent, which
comprises a fire brick or bricks or combinations of fire bricks provided with orifices
for use on the top of the fire bridge through which orifices the heated air is discharged
horizontally from the air box or passages in the bridge.
Although in the illustration herein given of the application to a Cornish boiler, one
air pipe or passage only is described for conveying the air from the bottom of the fire
bridge, to the air box at the back of the fire bridge, I do not confine myself to one
pipe, as several such pipes may be used, one large lower pipe may be used in
connection with several smaller upper pipes, each of which may have a separate
opening into the air bridge, or all of which may converge into one central opening
in the air bridge.
The nature of my invention will be better understood on reference to the accompanying
two sheets of drawings in which-
Fig. 1, (Sheet 1), is a longitudinal section of the Furnace tube of a Cornish or
Lancashire Steam Boiler.
Fig. 2, (Sheet 1) being a plan of the same shewing the bridge partly in section
and half the fire bars removed.
Fig. 3, (Sheet 2) is a cross section of the same on the line A. B.
Fig. 4, (Sheet 2,) is a longitudinal section of the fire bridge and air connections
shewing an alternative arrangement, where several smaller upper pipes may be used,
all of which have a separate opening into the air bridge.
Fig. 5, (Sheet 2), being a cross section of the same on the line C. D. and
Fig. 6 (Sheet 2), being a cross section of a furnace tube, so fitted, on the
line A. B.
The same letters refer to similar parts throughout the several views.
a,
is the plate of the furnace tube.
b, b, are the fire bars.
c, is the fire bridge.
d, is the air box in the fire bridge.
e, e, is an opening or openings for the admission of a pipe or pipes to the rear of
the bridge.
ff, is the cover brick or cover bricks.
g and g, is an air pipe or pipes for the admission of air to the back of the bridge, and
h, is a connecting pipe or pipes by which the air is conducted backwards
towards the bridge, to the opening or openings e, e, in the air box d, previously
referred to.
i, is a junction air box which in some cases may be dispensed with, and a round
bend may be employed as shewn by the dotted lines, or in other cases where the length
of these pipes are restricted, the pipe g, and the pipe or pipes h, and the junction i,
may all be cast in one piece.
In some cases the pipe g, may be stopped short at the bridge dispensing with the
length g¹, below the fire bars a grid or valve may be placed at j, or at k, in the pipe g',
or g, for regulating the admission of air, or a steam jet may be introduced at either of
these points should circumstances require it, in some cases even when the air pipe g, is
brought to the front of the boiler, the joint shewn at K, may be dispensed with. The
arrows indicate the direction of the air from the front of the boiler or the ash pit to the

page_text: discharge orifices in the cover brick or bricks f on the bridge, at which point the
heated air will mix and inflame with the gases distilled from the fuel on the fire grate
thereby promoting more perfect combustion and economy of fuel.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I wish it to be understood that I do
not claim any novelty for the introduction of heated air through the bridge of the
furnace for obtaining more perfect combustion of fuel, nor the employment of an air
box formed in the brickwork of the bridge, but what I do claim is:-
(1) The arrangement and combination of parts constituting the pipes and connections
from the front to the rear of the fire bridge through which the air is conducted to
the air box in the bridge and heated on its passage thereto, in the manner and
for the purposes substantially as herein described and illustrated in the accompanying
drawings.
(2) Improvements in apparatus and appliances for obtaining more perfect
combustion of fuel in the furnaces of steam generators substantially as herein before
set forth and illustrated.