IMPROVEMENTS IN FIRE-BARS, AND IN THE CONSTRUCTION OF STEAM BOILER AND OTHER FURNACES FOR THE CONSUMPTION OF SMOKE AND ECONOMISATION OF FUEL THEREIN.
Year: 1875

page_text: LETTERS PATENT to Francis Erskine, of the City of Manchester,
Engineer, for the Invention of "IMPROVEMENTS IN FIRE-BARS, AND
IN
THE CONSTRUCTION OF STEAM BOILER AND OTHER FURNACES FOR THE
CONSUMPTION OF SMOKE AND ECONOMISATION OF FUEL THEREIN.'
"
PROVISIONAL SPECIFICATION left by the said Francis Erskine at the
Office of the Commissioners of Patents, with his Petition, on the
29th April 1875.
I, FRANCIS ERSKINE, of the City of Manchester, Engineer, do hereby
declare the nature of the said Invention of "IMPROVEMENTS IN FIRE-
BARS, AND IN THE CONSTRUCTION OF STEAM BOILER AND OTHER FURNACES FOR
THE CONSUMPTION OF SMOKE AND ECONOMISATION OF FUEL THEREIN," to be as
follows:-
1:
The object of this Invention is to so construct steam boiler and other
furnaces as to increase the supply of air entering between the fire-bars,
and also to provide a means of heating a supply of air, which may be

page_text: caused to enter the furnace either through the dead plate or above the
bridge. For these purposes I prefer to construct my improved fire-bars
with corrugations on each of their vertical sides, instead of having their
sides parallel to each other as usually practised; and in casting this
description of fire-bar I arrange a tubular elbow at the back extremity
of each fire-bar next to the bridge, this elbow forming one casting with
the fire-bar. I am thus enabled to form a heating medium for a supply
of air which passes through these elbows from the ash-pit to the back of
the bridge, and such elbows are bricked up in the bridge and thus
prevented being burnt, the entrance of air through these elbows being
controlled by a damper.
In admitting hot air through the dead plate I form a chamber
beneath such dead plate, and from this chamber I arrange a series of
pipes to project beneath the fire-bars in the direction of the length of
the furnace. These pipes are open at one end and form the support for
corrugated fire-bars, which are arranged transversely in the furnace
with slots resting upon the pipes herein-before mentioned, and thus
such pipes are heated by their immediate contact with the fire-bars, and
in their turn heat the air passing through them into the chamber
situated beneath the dead plate. This chamber is provided with a
false bottom or damper and upright partition plate, which serves to
prevent such chamber being choked up with fuel, and also affords a
ready means of withdrawing any fuel or cinders which may find their
way into such chamber.
The hot air finds admittance from the dead plate chamber into the
furnace either through a transverse opening formed in the dead plate
and covered by a hinge plate, or a tube may be carried up from the
dead plate at one side and be joined again to the dead plate at the other
side, this tube being perforated or formed with slits to admit the hot air
above the furnace.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Francis Erskine in the Great Seal Patent Office
on the 29th October 1875.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of April, in the year of our
Lord One thousand eight hundred and seventy-five, in the thirty-ninth
year of Her reign, did, for Herself, Her heirs and successors, give and
3 grant unto me, the said Francis Erskine, Her special licence that I, the
said Francis Erskine, my executors, administrators, and assigns, or such
others as I, the said Francis Erskine, 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 of Man, an Invention for "IMPROVEMENTS IN FIRE-BARS, AND IN THE CON-
STRUCTION OF STEAM BOILER AND OTHER FURNACES FOR THE CONSUMPTION OF SMOKE
AND ECONOMISATION OF FUEL THEREIN," upon the condition (amongst others)
that I, the said Francis Erskine, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
scals, 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 within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Francis Erskine, do hereby declare
the nature of my said Invention, 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 this Invention is to so construct steam boiler and other
furnaces as to increase the supply of air entering between the fire-bars,
and also to provide a means of heating a supply of air, which may be
caused to enter the furnace either through the dead plate or above the
bridge.
And in order that this my said Invention may be the more readily
understood and carried into practical effect, I have hereunto anexed a
Drawing (to a scale of about one inch to the foot) illustrative of my
Invention, similar letters marked on the several views being used to
denote similar parts."
Fig. 1 is a plan of the bottom of a furnace constructed in accordance
with my Invention shewing the arrangement of the fire-bars and the

page_text: along the line a—b.
Fig. 3 illustrates a plan, and Fig. 4 a side view of one of the fire-bars
shewn removed from the furnace.
Fig. 5 is a side view of one of the transverse bearers for supporting
the pipes, which in their turn support and receive heat from the
fire-bars.
Fig. 6 is a side view, partly in séction, of a fire-bar and tubular elbow
forming another modification of my Invention for heating and admitting
air above the bridge.
In carrying out my Invention I construct my improved fire-bars A
with corrugations on each of their vertical sides as illustrated, instead
of having their sides parallel to each other as usually practised; and in
casting this description of fire-bar I sometimes arrange a tubular
elbow B (see Fig. 6) at the back of each fire-bar lying next to the
bridge, this elbow forming one casting with the fire-bar. I am thus
enabled to form a heating medium for a supply of air which passes
through these elbows from the ash-pit to the back or top of the bridge,
in which case such elbows are bricked up in the bridge, and are thus
prevented being burnt, the entrance of air through these elbows being
controlled if desirable by a damper.
In admitting hot air through the dead plate C, as seen in Figs. 1
and 2, I form a chamber D beneath such dead plate, and from this
chamber I arrange a series of pipes E to project beneath the fire-bars A
in the direction of the length of the furnace. These pipes all open at
their rear extremities into one common casting F, which receives its
supply of air from the ash-pit. The transverse castings or bearers G
(see side view, Fig. 5) form the intermediate supports for the pipes E,
which in their turn support the corrugated fire-bars A, which either
rest directly upon them, as seen more clearly in Fig. 2; or slots may
be cast upon the under sides of such fire-bars to grasp the pipes E.
The fire-bars in the centre of the furnace are arranged transversely,
and if not sufficiently long to occupy the whole width of the furnace,
then the extra width may be made up with such fire-bars arranged in
the longitudinal direction on either side, as seen in Fig. 1. The pipes E

page_text: are thus heated by their immediate contact with the fire-bars, and in
their turn heat the air passing in the direction of the arrows, through
them into the chamber D situated beneath the dead plate C, from
whence such heated air escapes into the furnace through the grating H,
which may be covered by a sliding or hinged plate to control the
admission of heated air to the greatest nicety. I is a false bottom to
the chamber D capable of being withdrawn from the front, and whereby
any fuel or cinders or dust which may find its way into such chamber
may be allowed to drop out into the ash-pit beneath; or instead of
finding admittance into the furnace through the grating H a tube or
pipe may be carried up inside the furnace from the dead plate at one
side, and be connected again to the dead plate at the other side, this
tube being perforated or formed with slits to admit the hot air at any
required angle above the furnace.
It will be readily apparent that this introduction of heated air into
the furnaces of steam boilers and other furnaces promotes the con-
sumption of smoke and economisation of fuel therein.
Instead of using corrugated fire-bars it will be obvious that the
ordinary fire-bars might be used in conjunction with my improved
system of heating air on its passage to a hollow dead plate, and therefore
I do not restrict myself to the use of corrugated fire-bars.
Having thus particularly described and ascertained the nature of this
my said Invention, together with the best methods with which I am
acquainted for carrying the same into practical effect, I wish it to be
understood that I do not confine myself to the precise details, relative
proportions, or dimensions of the various parts of the apparatus hercin-
before described and illustrated on the accompanying Drawing, as the
same may be considerably varied without departing from the Invention,
and I claim,―
1st. The hollow dead plate in combination with the pipes E when
used as a support for the fire-bars, and whereby the air passing through
such pipes is heated in its passage into the furnace, as and for the
purposes herein-before described and illustrated on the accompanying
Drawing.
5 2nd. The fire-bars with corrugated sides in conjunction with hollow
elbows forming a heating medium and passage for admitting heated air

page_text: to the furnace above the bridge, as and for the purposes herein-before
described and illustrated on the accompanying Drawing.
In witness whereof, I, the said Francis Erskine, have hereunto
set my hand and seal, this Twenty-eighth day of October, in
the year of our Lord One thousand eight hundred and seventy-
five.