IMPROVEMENTS IN STEAM BOILER FURNACES
Year: 1866

page_text: LETTERS PATENT to James Daly Dow, of Liverpool, in the County of
Lancaster, Mechanical Engineer, for the Invention of "IMPROVEMENTS
IN STEAM BOILER FURNACES."
Sealed the 28th August 1866, and dated the 1st March 1866.
PROVISIONAL SPECIFICATION left by the said James Daly Dow at the
Office of the Commissioners of Patents, with his Petition, on the
1st March 1866.
I, JAMES DALY Dow, of Liverpool, in the County of Lancaster, Me-
chanical Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN STEAM BOILER FURNACES," to be as follows (that is
to say):-
This Invention relates to a novel construction of furnaces of steam
boilers for land or marine purposes, whereby the smoke from the fuel is
nearly or completely consumed, or rather prevented forming, and whereby
in one modification of this Invention the heating surface may be increased
by means of hollow bars or tubes, through which the water con-

page_text: stantly circulates from the feed water or otherwise, and it is expected a great
saving of fuel will be effected, and no clinkers and little ashes will be
formed.
To construct a boiler according to the first modification of this Invention
the furnace is formed above the ash-pit, which is closed in front.
The bars of the furnace are formed hollow or tubular and arranged
lengthways or transversely, but by preference transversely, but instead of
being placed as fire-bars of furnaces now usually are in ordinary
steam boilers, that is to say, lower at the rear than at the front, these hollow
bars or tubes are arranged to be higher at the back than at the front of
the furnace, or they may be placed horizontally. The ash-pit, which in
ordinary boilers is constructed open in front, is in these improved furnaces
closed, and the ordinary furnace doors are dispensed with during the time
the furnaces are in operation. The check or stop at the back of the furnace
extends from the crown of the furnace chamber downwards the required dis-
tance, entirely closing the back of the furnace chamber in rear
of the grate. The heated gases, the products of combustion, pass down
between the bars into the ash-pit and thence through a flue extending from
the rear of the ash-pit, which flue or flues may be carried in any convenient
or desired direction, and, which flues may be tubular or otherwise. These
hollow bars or tubes may be constructed of cast or wrought metal, and by
preference, when they arranged transversely, it is preferred to form
them slightly arched and arrange them 80 that the ends of each
hollow bar open into a narrow water space or chamber running along each
side of the furnace grate, and which longitudinal water spaces have lateral
communications with the interior of the boiler, and in most cases it
is preferred to first pass the feed water by means of a suitable pipe, or
pipes into these lateral water spaces, thus insuring a perfect circulation of
the water through the hollow bars or tubes.
The action of this improved furnace is as follows:-The fuel is laid on
the hollow bars or tubes and is there ignited, the flame descending down
between the bars into the ash-pit, and thence passing into and through the
flue which opens into the ash-pit. When it is desired to damp the fire a
cover or door is used to close the furnace mouth, and a small lid or cover
fitted into the vertical partition closing the front of the ash-pit is opened,
thus allowing a current of air to pass through the ash-pit and through the
flue of the boiler, which will carry with it any noxious gases generated by
the then smouldering fuel. Where an increased heating surface is not desired

page_text: the hollow bars or tubes may be dispensed with, in lieu of which a series of
narrow fire-brick arches may be constructed so as to form the bottom
of the furnace, the fire-brick arches being placed sufficiently in rear
of each other to allow the heated gases, the products of combustion,
to pass down through the spaces between them and into the enclosed
ash-pit, and thence through the boiler flue or flues which extend from the
ash-pit through the boiler. In some cases a midfeather of fire-brick or
fire-tile may be formed in the ash-pit to support the floor of the furnace. In
lieu of the series of fire-brick arches described an arch of perforated fire-brick
or fire-tiles may be used, or the floor of the furnace chamber may be constructed
with an open check fire-brick arch.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Daly Dow in the Great Seal Patent Office on the
1st September 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
DALY Dow, of Liverpool, in the County of Lancaster, Mechanical Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of March, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said James Daly Dow, Her special licence that I, the said James
Daly Dow, my executors, administrators, and assigns, or such
others as I, the said James Daly Dow, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
Man, an Invention for "IMPROVEMENTS IN STRAM BOILER FURNACES," upon
the condition (amongst others) that I, the said James Daly Dow, my exe-
cutors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office

page_text: and rumcurately arter The date of the Salu
Letters Patent.
NOW KNOW YE, that I, the said James Daly Dow, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
This my said Invention relates to a novel construction of furnaces of steam
boilers for either land or marine purposes, whereby the smoke from the fuel
is nearly or completely consumed, or rather prevented forming, and
whereby in one modification of this Invention the heating surface may
be increased by means of hollow bars or tubes, through which the water
constantly circulates from the feed water or otherwise, and it is expected
a great saving of fuel will be effected, and no clinkers and little ashes will
be formed.
To construct a boiler according to the first modification of this my said
Invention the furnace is formed above the ash-pit, which is closed in front.
The bars of the furnace are formed hollow or tubular and arranged length-
ways or transversely, but by preference transversely, but instead of being
placed as fire-bars of furnaces now usually are in ordinary steam boilers, that
is to say, lower at the rear than at the front, these hollow bars or tubes are
arranged to be higher at the back than at the front of the furnace, or they
may be placed horizontally. The ash-pit, which in ordinary boilers is
constructed open in front, is in these my improved furnaces closed, and
the ordinary furnace doors are dispensed with during the time the furnaces
are in operation. The check or stop at the back of the furnace extends
from the crown of the furnace chamber downwards the required distance,
entirely closing the back of the furnace. chamber in rear of the grate.
The heated gases, the products of combustion, pass down between the bars
into the ash-pit, and thence through a flue extending from the rear of the
ash-pit, which flue or flues may be carried in any convenient or desired
direction, and which flues may be tubular or otherwise. These hollow
bars or tubes may be constructed of cast or wrought metal, and by pre-
ference, when they are arranged transversely, I prefer to form them slightly
arched, and arrange them so that the ends of each hollow bar opens into a
narrow water space or chamber running along each side of the furnace
grate, and which longitudinal water spaces have lateral communications
with the interior of the boiler, and in most cases it is preferred to pass the
feed water by means of a suitable pipe or pipes into these lateral water

page_text: spaces, thus insuring a perfect circulation of the water through the hollow
bars or tubes.
The action of this my improved furnace is as follows:-The fuel is laid
on the hollow bars or tubes and is there ignited, the flame descending
down between the bars into the ash-pit, and thence passing into and
through the flue which opens into the ash-pit. When it is desired to
damp the fire a cover or door is used to close the furnace mouth, and a
small lid or cover fitted into the vertical partition closing the front of the
ash-pit is opened, thus allowing a current of air to pass through the ash-
pit and through the flue of the boiler, which will carry with it any noxious
gases generated by the then smouldering fuel. Where an increased heating
surface is not desired the hollow bars or tubes may be dispensed with, in
lieu of which a series of narrow fire-brick arches may be constructed so
as to form the bottom of the furnace, the fire-brick arches being placed
sufficiently in rear of each other to allow the heated gases, the products of
combustion, to pass down through the spaces between them and into the
enclosed ash-pit, and thence through the boiler flue or flues which extend
from the ash-pit through the boiler. In some cases a midfeather of fire-
brick or fire-tile may be formed in the ash-pit to support the floor of the
furnace. In lieu of the series of fire-brick arches described an arch of
perforated fire-brick or fire-tiles may be used, or the floor of the furnace
chamber may be constructed with an open check fire-brick arch. In some
cases it may be found desirable to lay the fuel upon a grating or ordinary
fire-bars above the transverse or longitudinal hollow water bars described,
in which case the flame descends through between the grating and hollow
bars into the ash-pit, and from thence through the flue or flues in rear
thereof, and in other cases it will be found of advantage to use a double
set of hollow bars arranged in line above one another so that the descending
flame and heated gases, the products of combustion, will impinge against
the external surface of the lower set of bars in descending into the
ash-pit.
:
That this my said Invention may be the more readily seen and under-
stood I have hereunto annexed Drawings of so much of several boilers
as is necessary to illustrate the practical application of several modifications
of the Invention, and by which any person acquainted with the art will
readily be able to apply the Invention to ordinary steam boilers without
further explanation. Like letters and figures marked on the annexed
Drawings are used to denote similar parts.

page_text: Figure 1 is a longitudinal sectional elevation of an ordinary flue boiler,
showing my improved furnace applied thereto, constructed with a double
series of water bars and a hollow check plate at the back of the furnace,
and Figure 2 is a transverse sectional elevation of the same; Figures
3 and 4 are longitudinal and transverse sectional elevations of another flue
boiler with a single set of water bars, in which the products of combustion
are carried into the ash-pit and thence into segmental flues, which are
formed by a muffle or arch thrown over the furnace, the flame and heated
gas being carried down through between the hollow bars, from whence it
passes up into the segmental flues on each side of the furnace, as indicated
by the arrows; Figure 5 is a vertical sectional elevation of one modification
of my Invention applied to a multitubular boiler, and Figure 6 is an
end view or front elevation of the same, showing the doors for closing the
ash-pit in front.
A, shell of the boiler; B, the furnace tube; C, hollow transverse fire-
bars; D (Figure 1), hollow check piece or water space in rear end of the
furnace; E (Figure 1), fire-bridge; F, plate or arch over furnace, forming
segmental flues on each side of the furnace; in this arrangement a water
space may be used in place of the single plate shown in the Drawing;
G (Figure 5), check plate at the back of the furnace for causing the
draught to descend through the bars into the ash-pit and through H, the
boiler tubes; K and K¹ (Figure 6) are doors for closing the front of the
ash-pit.
Having now fully described and ascertained the nature of this my said
Invention, and the best means I am acquainted with for carrying the same
into practical effect, I wish it to be understood that I do not confine myself
to the several dimensions or proportions of the several parts of the appa-
ratus herein-before described and illustrated, as it will be readily seen that
the same may be considerably varied without departing from the Invention;
but what I claim as new and my Invention is,---
First, closing the front of the ash-pit, causing the flame and products of
combustion to descend into the ash-pit, and passing the same from the rear
thereof through tubular or other flues, substantially in the manner and for
the purposes herein-before described and set forth.
Secondly, causing the flame and other products of combustion to descend
through the furnace bars, and turning the same into the segmental flues on
each side of the furnace, substantially in the manner and for the purposes
herein-before described and illustrated by Figures 3 and 4.

page_text: And, lastly, the general arrangement and combination of the various
parts of the apparatus substantially in the manner and for the purposes
herein-before. described and set forth.
In witness whereof, I, the said James Daly Dow, have hereunto
set my hand and affixed my seal, this Thirty-first day of August,
in the year of our Lord One
Lord One thousand eight hundred and
sixty-six.
Witness,
WILLIAM WALKER,
of 44, Castle Street,
Liverpool.
JAMES DALY (L.S.) DOW.