IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES FOR PREVENTING OR LESSENING SMOKE AND EFFECTING MORE PERFECT COMBUSTION OF THE FUEL EMPLOYED THEREIN.
Year: 1870

page_text: LETTERS PATENT to Thomas Hydes and John Emil Bennett, both of
Sheffield, in the County of York, for the Invention of "IMPROVEMENTS
IN THE CONSTRUCTION OF FURNACES FOR PREVENTING OR LESSENING SMOKE AND
EFFECTING MORE PERFECT COMBUSTION OF THE FUEL EMPLOYED THEREIN.
"
Sealed the 26th May 1871, and dated the 80th November 1870.
PROVISIONAL SPECIFICATION left by the said Thomas Hydes and
John Emil Bennett at the Office of the Commissioners of Patents,
with their Petition, on the 80th November 1870.
We, THOMAS HYDES and JOHN EMIL BENNETT, both of Sheffield, in
the County of York, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE CONSTRUCTION OF FURFACES FOR PREVENTING OR
LESSENING SHOKE AND EXPECTING MORE PERFECT COMBUSTION OF THE FUEL
EMPLOYED THEREIN," to be as follows:-
This Invention relates to two principal parts of furnaces, namely, the
fire-doors and bridges thereof, and consists in constructing and operating
those said parts in the following manner and by the following means:-
First. As regards the doors of furnaces, we propose to construct them
as follows:-We form the fire-door as a box perforated on that side that

page_text: is nearest to the inside of the furnace, and the opposite side or front of
the said door we form solid and adjustable, that is to say, we form the
aforesaid perforated part and sides of the box of the door of one piece,
and we connect the front or solid part of the furnace door to the box
part of the door by means of levers or rods so arranged and con-
nected to each of these parts as to enable the aforesaid solid part or front
of the door to be moved outwards in a parallel direction from the fixed
portion or face of the box of the door by means of an adjusting screw
and nut attached to the box of the furnace door; by these means we are
enabled to adjust the space between the aforesaid moveable and fixed :
parts of the furnace door, so as to admit any required quantity of air
into the furnace to assist in supporting combustion of the fuel therein,
and to which the aforesaid improved door is applied; and further, by
this mode of admitting air through the furnace door the air instead of
entering the furnace cold becomes heated by coming into contact with :
the hot surfaces of the door plates and front of the boiler, before entering
into and mixing with the gases in the furnace, and it is this peculiar
construction of the doors of furnaces that constitutes the particular
feature of novelty in this part of our said Invention.
We now proceed to describe that part of our said Invention which a
relates to the bridges of furnaces, the novelty of which consists in
constructing the bridge of a furnace double or with two walls as
follows: The first wall situated nearest to the grate bars is laid on
bearers about level with the under surface of the grate bars, the top of
the wall reaching some inches above the level of the top of the grate :
bars, leaving a sufficient space above the top of the wall and the top of
the fluo of the boiler to allow free passage of the gases from the fire on
the grate bars. The back part of this first wall is cut away in a bevilled
or sloping direction in order to prevent the accumulation of fuel or ashes
on the top of the bridge, and which would otherwise impede the
draught. The second wall is built from the bottom of the ash-pit, and
the top of it is level or thereabouts with the top of the first wall before
named. The front part of this wall is also bevilled off the same as the
first wall and for the same purpose, namely, for preventing the accumu-
lation of ashes or fuel on the top of the wall of the bridge. And we a
would here remark that the space thus formed by the bevels of the two
walls of the bridges serves also as a trap or hopper to receive and

page_text: discharge the fuel which might be accidentally thrown over the bridge,
that is to say, between the first and second walls above named a space
of some inches is allowed for the purpose of admitting a door made
either with or without perforations as required; this door may be hinged
and opened or closed by any suitable means for the purpose of dis-
charging any accumulation of ashes which may be formed between the
bridges or walls, and also to regulate the necessary quantity of air for
the
proper combustion of the fuel.
A further advantage and novelty in the above mode of constructing
the bridges of furnaces consists in employing, if desirable, the space
between the two aforesaid walls of the bridge as an auxiliary furnace to
contain fuel for heating and consuming the gases passing from the fuel
or the furnace bars.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Hydes and John Emil Bennett in the
Great Seal Patent Office on the 30th May 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
HYDES and JOHN EMIL BENNETT, both of Sheffield, in the County of
York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of November, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Thomas Hydes and John Emil Bennett,
Her special licence that we, the said Thomas Hydes and John Emil
Bennett, our executors, administrators, and assigns, or such others as
we, the said Thomas Hydes and John Emil Bennett, 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 "IMPROVEMENTS IN
THE CONSTRUCTION OF FURNACES FOR PREVENTING OR LESSENING SHOKE AND
EFFECTING MORE PERFECT COMBUSTION OF THE FUEL EMPLOYED THEREIN," upon

page_text: .
the condition (amongst others) that we, the said Thomas Hydes and
John Emil Bennett, our executors or administrators, by an instrument
in writing under our, 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 we, the said Thomas Hydes and John Emil
Bennett, do hereby declare the nature of the said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, that is to say :-
This Invention relates to two principal parts of furnaces, namely, the
fire-doors and bridges thereof, and consists in constructing and operating
those said parts in the following manner and by the following means:—
First. As regards the doors of furnaces we propose to construct them
as follows:-We form the fire-door as a box perforated on that side that
is nearest to the inside of the furnace and the opposite side or front of the
said door we form solid and adjustable, that is to say, we form the afore-
said perforated part and sides of the box of the door of one piece, and
we connect the front or solid part of the furnace door to the box part
of the door by means of levers or rods so arranged and connected to
each of those parts as to enable the aforesaid solid part or front of the
door to be moved outwards in a parallel direction from the fixed portion
or face of the box of the door by means of an adjusting screw and nut
attached to the box of the furnace door. By these means we are enabled
to adjust the space between the aforesaid moveable and fixed parts of
the furnace door so as to admit any required quantity of air into the
furnace to assist in supporting combustion of the fuel therein, and to
which the aforesaid improved door is applied; and further, by this mode
of admitting air through the furnace door, the air instead of entering
the furnace cold becomes heated by coming into contact with the hot
surfaces of the door plates and front of the boiler before entering into
and mixing with the gases in the furnace, and it is this peculiar
construction of the doors of furnaces that constitutes the particular
feature of novelty in this part of our said Invention.
We now proceed to describe that part of our said Invention which
relates to the bridges of furnaces, the novelty of which consists in con-
3

page_text: structing the bridge of a furnace double or with two walls as follows:-
The first wall situated nearest to the grate bars is laid on bearers about
level with the under surface of the grate bars, the top of the wall
reaching some inches above the level of the top of the grate bars, leaving
a sufficient space above the top of the wall and the top of the flue of the
boiler to allow free passage of the gases from the fire on the grate bars.
The back part of this first wall is cut away in a bevilled or sloping
direction in order to prevent the accumulation of fuel or ashes on the
top of the bridge, and which would otherwise impede the draught. The
second wall is built from the bottom of the ash-pit, and the top of it is
level, or thereabouts, with the top of the first wall before named. The
front part of this wall is also bevilled off the same as the first wall, and
for the same purpose, namely, for preventing the accumulation of ashes
or fuel on the top of the wall of the bridge. And we would here
remark, that the space thus formed by the bevils of the two walls of the
bridges serves also as a trap or hopper to receive and discharge the fuel
which might be accidentally thrown over the bridge, that is to say,
between the first and second walls above named, a space of some inches
is allowed for the purpose of admitting a door made either with or
without perforations as required; this door may be hinged and opened
or closed by any suitable means, for the purpose of discharging any
accumulation of ashes which may be formed between the bridges or
walls, and also to regulate the necessary quantity of air for the proper
combustion of the fuel.
A further advantage and novelty in the above mode of constructing
the bridges of furnaces consists in employing if desirable the space
between the two aforesaid walls of the bridge as an auxiliary furnace to
contain fuel for heating and consuming the gases passing from the fuel
on the furnace bars.
And in order to explain this Invention more clearly, we will now
proceed to describe its construction and mode of operation, reference
being had to the illustrative Sheet of Drawing accompanying this
Specification, and to the numeral figures and letters of reference marked
thercon respectively as follows:-
DESCRIPTION OF THE DRAWING.
Tie 1 is an elevation and Tie 2 a vertical seation of The 1 o

page_text: furnace door; Fig. 3 represents a front elevation of a Cornish boiler with
this Invention adapted thereto; Fig. 4 is a longitudinal and vertical
section of a portion of the said boiler and one of its furnaces. At each
of the above Figures similar letters of reference are placed upon
corresponding parts.
1
5
At Figs. 1 and 2 A marks a bracket cast upon the furnace door B;¨O
is a stud bolted to B; D, a door capable of sliding to and fro on C;
E are steady pins cast on the air door for preserving its parallel move-
iment. By pulling the door D outwards air may be admitted into tho
furnace through the door front and perforated plate G fixed to the 1
door B, and when sufficient air has been admitted the door D may
be closed.
"
.
We now proceed to describe the construction of the bridges of
furnaces, and manner of operating therewith according to this Invention,
as represented at Figs. 3 and 4 of the Drawing, where H marks a doublo 1
bridge of fire-clay resting on castings a, b, and the cross wall I; K is a
balance flap hinged at c to the casting a; L is a rod connected to K
for opening and closing the flap K when desired; M is a hole through
which the rod L passes; d are notches in Ĺ to keep the flap open any
required distance; N is a hole for admitting air into the furnace at 2
all times.
.
Having now fully described and set forth the nature and object of our
said Invention for improvements in the construction of furnaces for
preventing or lessening smoke and effecting more perfect combustion
of the fuel employed therein, together with the means by which it may 2
be effected, we would remark that we do not claim to have invented a
double bridge, as we are aware of what are termed split bridges having
been in use in furnaces for many years past; but what we claim as our
Invention and desire to secure by Letters Patent is as follows :—
. We claim sloping the walls of the bridges of furnaces into a hopper 3
shape to receive any fuel or ashes that would otherwise rest on the top
of the walls of the said bridges; also adapting a door between the two
walls of the bridges for discharging the fuel therefrom.
Secondly. Making the solid front of a furnace door to move away
from the perforated back and box part of such said door in a parallel 3
direction to regulate the quantity of air admitted into the furnace, and

page_text: cause it to be thus heated before entering the furnace, substantially as
above described and represented.
JOHN EMIL BENNETT. (L.s.)
In witness whereof, I, the said John Emil Bennett, one of the
parties hereto, have hereunto set my hand and seal, this Twenty-
seventh day of May, in the year of our Lord One thousand eight
hundred and seventy-one.