IMPROVEMENTS IN STEAM BOILERS AND FURNACES
Year: 1867

page_text: UT
James M'Neil, of Brunswick Road, Bromley, both in the County of
Middlesex, for the Invention of "IMPROVEMENTS IN STEAM BOILERS AND
FURNACES."
Sealed the 15th April 1868, and dated the 17th October 1867.
PROVISIONAL SPECIFICATION left by the said William Tredgold and
James McNeil at the Office of the Commissioners of Patents, with their
Petition, on the 17th October 1867.
We, WILLIAM TREDGOLD, of Russell St., Blackwall, and JAMES MCNEIL,
of Brunswick Road, Bromley, both in the County of Middlesex, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN STEAM BOILERS
AND FURNACES," to be as follows:-
Our Invention relates to improvements in the construction of steam boilers
and furnaces with a view to obtain a largely increased heating surface,
economy in fuel, and an almost entire consumption of smoke. To effect this
we provide the furnace with hollow fire-bars which pass under and beyond
the bridge, and are firmly fixed at their rear ends, where they communicate
with the water space of the boiler. These fire-bars incline downwards toward
the front where they terminate in a hollow chamber, resting simply agains
the sides of the furnace and free to move sufficiently to allow for the expansion
and contraction of the fire-bars. The water supplied to the boiler first passes
[Price 8d1

page_text: into a water head situate within the smoke box, where it becomes heated
preparatory to entering; from said water head the water passes through a
suitable pipe into the chamber supporting the front ends of the hollow fire-
bars before mentioned, through which latter it is forced in the form of jets
by the pressure of the supply by means of nozzles placed in the end of each
hollow fire-bar, the inclination of said fire-bars facilitating the passage of the
water and steam contained into the boiler. Air is admitted to the fuel at the
front of the furnace above the fire-bars, the ash-pit being completely closed at
all times except for the removal of cinders. By this arrangement the
products of combustion first pass down through the fire-bars and then up
again between them behind the bridge, returning through the smoke tubes of
the boiler into the smoke box at the front of the same, in which is the water
head for heating the water contained, as above mentioned, before it enters
the boiler, thereby effecting a saving of fuel. The heat passing twice through
between the hollow fire-bars as well as through the smoke tubes of the
boiler affords an increased heating surface, at the same time that the smoke
is consumed by passing downwards through the incandescent part of the
fire.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Tredgold and James McNeil in the Great Seal Patent
Office on the 17th April 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
TREDGOLD, of Russell Street, Blackwall, and JAMES MCNEIL, of Brunswick
Road, Bromley, both in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of October, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirty-first year
of Her reign, did, for Herself, Her heirs and successors, give and grant
the said William Tredgold and James M'Neil, Her special
licence that we, the said William Tredgold and James M"Neil, our exc-
cutors, administrators, and assigns, or such others as we, the said William
Tredgold and James M'Neil, our 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 "Im

page_text: PROVEMENTS IN STEAM BOILERS AND FURNACES," upon the condition (amongst
others) that we, the said William Tredgold and James McNeil, our
executors or administrators, by an instrument in writing under our 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 per-
formed, 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 we, the said William Tredgold and James McNeil
do hereby declare the nature of our said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Sheet of Drawings
hereunto annexed, and to the letters and figures marked thereon (that is to
say):-
Our Invention relates to improvements in the construction of steam boilers
and furnaces with a view to obtain largely increased heating surface,
economy in fuel, and an almost entire consumption of smoke. To effect this
we provide the furnace with hollow fire-bars which pass under and beyond
the bridge and are firmly fixed at their rear ends, where they communicate
with the water space of the boiler. These fire-bars incline downwards towards
the front where they terminate in a hollow chamber, resting simply against
the sides of the furnace and free to move sufficiently to allow for the expansion
and contraction of the fire-bars. The water supplied to the boiler first passes
into a waterhead situate within the smoke box, where it becomes heated pre-
paratory to entering the boiler. The water passes from said waterhead
through a suitable pipe into the chamber supporting the front ends of the
hollow fire-bars before mentioned, through which latter it is forced in the
form of jets by the pressure of the supply by means of nozzles placed in the
end of each hollow fire-bar, the inclination of said fire-bars facilitating the
passage of the water and steam contained therein into the boiler. Air is
admitted to the fuel at the front of the furnace above the fire-bars, the ash-
pit being completely closed at all times, except for the removal of cinders.
By this arrangement the products of combustion are first caused to pass down
through the fire-bars and then up again between them behind the bridge,
returning through the smoke tubes of the boiler into the smoke box at the
front of the same, in which is the waterhead for heating the water contained,
as above mentioned, before it enters the boiler, thereby effecting a saving of
fuel. The heat and flame passing twice through between the hollow fire-bars
and through the smoke tubes of the boiler affords an increased heating surface,

page_text: Our Invention is represented in the accompanying Drawing, in which
Figure 1 shows a longitudinal section of our improved furnace and boiler taken
on the line 1, 2, Figure 2; Figure 2 is an end view of the boiler; while Figure 3
is a horizontal section of the hollow water chamber and fire-bars taken on the
line 3, 4, Figure 1.
a, a, are the hollow fire-bars passing under the water bridge b commu-
nicating with the water space c of the boiler, where they are firmly fixed.
The fire-bars a incline downwards towards the front where they are connected
to a hollow chamber d, which chamber simply rests against the sides of the
furnace, as seen in Figure 2, without being attached thereto in any way, so as
to move freely to allow for the expansion and contraction of the fire-bars d;
e is a waterhead placed in the smoke box i and communicating with the supply
by means of a suitable pipe i' into which the feed water first passes, where it
becomes heated preparatory to being supplied to the boiler. The waterhead e
communicates with the chamber d by means of a pipe through which the
water passes into a pipe g contained in the chamber c and provided with
nozzles corresponding to each of the hollow fire-bars a, the water being
forced through the nozzles into said fire-bars in the form of jets by the pressure
of the supply; the inclined position of said fire-bars a further facilitates the
circulation of the water and steam in the boiler. is a perforated door placed
above the chamber c to which it is hinged, and opening downwards for feeding
the fire and for the admission of air to the furnace, the draught (the direction
of which is indicated by the arrows) being regulated by means of the door k
as required. 1 is the ash-pit, which is kept completely closed at all times,
except for the removal of cinders, which is effected at the door provided for
the purpose. In this arrangement of boiler and furnace the products of com-
bustion are first caused to pass down through the fire-bars a and then up
again between them behind the bridge in the direction of the arrows, returning
through the smoke tubes m of the boiler into the smoke box in front of the
same, in which, as before mentioned, is placed the waterhead e for heating
the feed water. To facilitate this the waterhead e is provided with tubes or
passages corresponding to the smoke tubes m through which the products of
combustion are caused to pass. The heat and flame passing twice through
the hollow fire-bars a, as shown, and through the smoke tubes m of the boiler
affords an increased heating surface, at the same time that the smoke is almost

page_text: entirely consumed by passing downwards through the incandescent part of the
fire, as seen. By passing the feed water through the fire-grate in the manner
described a perfect and uniform circulation is obtained, while the whole of the
heating properties of the fuel are rendered available for the generation of steam;
there is further an entire absence of clinkers.
Having described the nature of our Invention, and the manner of perform-
ing the same, we declare that what we claim as our Invention to be protected
by the herein-before in part recited Letters Patent is,-
Constructing steam boilers and furnaces in the manner shown in the
Drawings, the whole combined and arranged as and for the purposes
described.
We also claim mounting the ends of the hollow fire-bars in a loosely-
fitting chamber to allow for their expansion and contraction in the manner
described.
We also claim heating and supplying the feed water to the boiler through
the furnace in the manner described.
In witness whereof, we, the said William Tredgold and James M°Neil,
have hereunto set our hands and seals, this Sixteenth day of April, in
the year of our Lord One thousand eight hundred and sixty-eight.
L