IMPROVE- MENTS IN STEAM BOILERS AND FURNACES FOR THE SAME
Year: 1884

page_text: I WILLIAM HENRY MIRFIN of the City of Manchester in the County of
Lancaster Engineer do hereby declare the nature of said Invention for "IMPROVE-
MENTS IN STEAM BOILERS AND FURNACES FOR THE SAME," to be as follows:-
The object of my Invention is to obtain a steam boiler of large heating surface
in little space, with the furnace or furnaces so arranged as to practically consume
the smoke, and my Invention consists firstly in a combination, arrangement and
construction of the shell, and one or more internal flues hereinafter called the fluo
or flues, as described in the Specification of Letters Patent granted to myself and
Emanuel Nield, Numbered 5050 and dated the 4th day of December A.D. 1880,
combined with tubes similar to those used in ordinary multi-tubular boilers such
tubes extending from end to end of the boiler and being arranged over and on
each side of the said flue or flues. The heat and heated gases from the furnace or
furnaces pass from one end of the boiler through the flue or flues, and then enter
a box or compartment at the end of the boiler and return to the other end of the
boiler through the said tubes and then enter another box or compartment and are
conducted to the chimney.
The small tubes forming part of the flue or flues as described in the said Mirfin
and Nield's Specification are or may be improved in construction according to my
present Invention by forming the end flanges of washers of metal blocked to the
angle-form, the tubes being secured to the angle-flange thus formed by rivets or
otherwise.
With the improved construction of boilers above described the furnace or furnaces
is or may be arranged according to my Invention under one end of the external
shell so that the heat and gases will first pass along the exterior of the shell then
through the flue or flues to one end and then return through the said tubes
extending from end to end, to the other end of the boiler.
Or the furnace or furnaces is or may be placed at one end of the boiler within
the internal flue or flues and the heat and gases pass as herein before described.
Secondly. My improvements in the furnace or furnaces applicable to the above
and other types of steam boilers consists in the construction of a chamber of metal,
placed immediately behind the fire bridge, which chamber has an inlet for air
regulated by a valve or damper; and an outlet through a series of small slits or
apertures, which disperse the air heated in passing through the chamber so as to
intimately mix it with the gases passing over the fire bridge from the burning fuel.
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page_text: The interior of the chamber has a series of ribs or partitions passing from the
top to the bottom of the chamber, which ribs or partitions are curved, corrugated
or placed in an inclined position so as to act upon and present a large surface to
air entering the chamber and thoroughly heat it before passes out through the
said slits or apertures. I also combine with such an arrangement of air heating
chamber at the fire bridge a diaphragm block or heater or igniter formed of fire
resisting material such as fire brick or asbestos, and I arrange this heater or igniter
in the form of a perforated disc by preference made solid or in pieces built and
secured or strapped together, and mount it on a base plate or block of metal or
other material placed on the bottom of the flue and moveable or adjustable to and
from the fire bridge as required this heater (being made hot by the heat from the
furnace) ignites the combined unburned gases and heated air.
These heaters or igniters according to my Invention are also arranged to swivel
on a vertical axis on the said base plate or block so as to be easily turned with the
flat side in the lengthway of the flue and thus allow a man to pass into and
through the flues to inspect or repair them.
t
These swivel heaters besides being arranged in the position above described are
also according to my Invention placed at intervals along the flue or Blues of the
boiler to help to mix the passing gases and bring them in closer contact with the
surface of the flues to be heated.
Dated this Second day of January 1884
PETER J. LIVSEY,
Petitioner's Agent.

page_text: I WILLIAM HENRY MIRFIN of the City of Manchester in the County of
Lancaster Engineer do hereby declare the nature of my Invention for IMPROVE-
MENTS IN STEAM BOILERS AND FURNACES FOR THE SAME, 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 obtain a steam boiler of large heating surface
in little space, with the furnace or furnaces so arranged as to practically consume
the smoke, and my Invention consists firstly in a combination, arrangement and
construction of the shell and one or more internal flues, hereinafter called the flue
or flues, as described in the Specification of Letters Patent granted to myself and
Emanuel Nield Numbered 5050 and dated the 4th day of December A.D. 1880,
combined with tubes similar to those used in ordinary multi-tubular boilers, such
tubes extending from end to end of the boiler and being arranged over or over
and on each side of the said flue or flues. The heat and heated gases from the
furnace or furnaces pass from one end of the boiler through the flue or flues, and
then enter a box or compartment at the end of the boiler and return to the other
end of the boiler through the said tubes and then enter another box or compartment
and are conducted to the chimney. With the improved construction of boilers
above described the furnace or furnaces is or may be arranged according to my
Invention under one end of the external shell, so that the heat and gases will first
pass along the exterior of the shell then through the flue or flues to one end and
then return through the said tubes extending from end to end to the other end
of the boiler, and then to the chimney. Or the furnace or furnaces is or may be
placed at one end of the boiler within the internal flue or flues and the heat and
gases pass as herein before described.
Secondly. My improvements in the furnace or furnaces applicable to the above
and other types of steam boilers consists in the construction of a chamber of metal
placed immediately behind the fire bridge which chamber has an inlet for air
regulated by a valve or damper, and an outlet through a series of small slits or
apertures, which disperse the air heated in passing through the chamber so as to
intimately mix it with the gases passing over the fire bridge from the burning
fuel. The interior of the chamber has a series of ribs or partitions passing from
the top to near the bottom of the chamber, which ribs or partitions are curved,
corrugated, or placed in an inclined position so as to act upon and present a large
surface to air entering the chamber and throughly heat it before
passes out
though the said slits or apertures. I also combine with such an arrangement of air
heating chamber at the fire bridge a diaphragm block or heater or igniter formed
of fire resisting or refractory material such as fire brick or asbestos and I arrange
this heater or ignitor in the form of a perforated disc by preference, made solid
or in pieces built and secured or strapped together and mount it on a base plate
or block of metal or other material placed on the bottom of the flue and movable
or adjustable to and from the fire bridge as required, this heater (being made hot
by the heat from the furnace) ignites the combined unburned gases and heated air.
These heaters or igniters according to my Invention are also arranged to swivel
on a vertical axis on the said base plate or block so as to be easily turned with the
flat side in the lengthway of the flue and thus allow a man to pass into and

page_text: through the flues to inspect or repair them. These swivel heaters besides being
arranged in the position above described are also according to my Invention, placed
at intervals along the flue or flues of the boiler to help to mix the passing gases
and bring them in closer contact with the surface of the flues to be heated.
Figs. 1, 2, 3, and 4 are each cross sections of boilers showing modifications
according to which the first part of my Invention may be carried into effect, and
Fig. 5 is a longitudinal section of my improved boiler with the furnace or furnaces
in the large flues and Fig. 6 a similar longitudinal section of a modification of my
improved boiler with the furnace or furnaces at one end and on the exterior of the
shell of the boiler according to the first part of my Invention.
In the Figures above referred to, a is the external shell of the boilers; b the
large flues combined with the small flue tubes d and d¹ according to the said
Mirfin and Nield's Specification.
My improved boilers are or may be formed with one two or more compound
flues b, d and d¹, constructed and arranged as described in the said Mirfin and
Nield's Specification, combined with a series of smaller horizontal tubes h extending
from end to end of the boiler, and arranged on each side, or over or both on each
side and over the large compound flues b, d and d'.
In the modification shown by Fig. 5 the gases after passing through the main
compound flue or flues enter a box or chamber h¹ having a hinged door h² to give.
ready access to the flues or tubes then they return through small tubes and
enter a box or chamber h³ from which they are conducted to the chimney.
In the modification shown by Fig. 6 the heated gases pass as described in
reference to the modification shown by Fig. 5 except that as the furnace or furnaces
are at one end at the exterior of the boiler the gases pass through an external
flue x under the exterior of the boiler and then as described in reference to Fig. 5
and after leaving the small tubes h they enter a chamber flue * connected with the
chimney flue h
A
Fig. 7 is a partial longitudinal section, on an enlarged scale of a furnace and
flue showing also part of the furnace bars, the air admitting and heating
arrangements, combined with an adjustable pivotting igniting disc or block
formed of any known or suitable fire resisting or refractory material.
Fig. 8 is a front view detached and on an enlarged scale of the hollow air heater
behind the fire bridge.
Figs. 9 and 10 are cross sections of the flues illustrating modifications of the
pivotting discs or blocks.
The Figs. 7 to 10, and Figs. 5 and 6 illustrate the second part of my Invention.
The dead plate k, fire bars k' and fire bridge 2 are or may be of any ordinary or
suitable construction and arrangement.
Behind the fire bridge there is a hollow metal box or this may be made or
considered to form the fire bridge protected by fire brick or other suitable fire
resisting or refractory material. This hollow box is about the width of the fire
bridge and is or may be arranged by preference with oblique transverse partitions (1
as shown in Fig. 8, or these partitions may be corrugated or waved to present
heating surface to the air passing from the ash pit which enters a hole formed
in the lower part of the front plate of the hollow box and passes up between and
against these partitions and then passes out through a series of slits or
perforations into a perforated segmental air distributor 14.
The hole in front of the hollow heating box is in communication with a short
oblong tube placed or built in the lower part of the fire bridge, which is arranged
with a grid face, the openings forming the grid corresponding with a plate & that
can slide in grooves formed in front of the tube part ³ as shown.
This slide 6 has a stud or pin in it that comes into the slot in an arm 1³ on
a shaft having its bearing in the frame of the short tube 15 at one end and in any
suitable support at the other end near the furnace door.

page_text: By oscillating this shaft the grid plate can be slided to and fro to open
or close or regulate the openings for air passing to the hollow box l.
Any other suitable valve arrangement may be substituted for that above-
described and illustrated by the Drawings.
The igniter is a disc or block of any suitable or ordinary fire resisting or
refractory material formed in one block, either perforated or not as illustrated by
Fig. 9 or it may be built up from pieces strapped or held together by a metal strap
secured to the boss or pivotting part m¹. Its shape is made to suit the cross section
of the flue in which it is used.
The discs or blocks m are arranged to swivel or pivot and the part m¹ forming
the pivot or foot may be either solid with or separate from the disc or block m
and this part m¹ may either be formed of the same refractory material as the disc
or block, or of metal.
The pivot part m¹ is or may be formed as shown in Figs. 7, 9, 5 and 6 being
carried on a base plate m² having a shape adapted to the bottom of the flue upon
which it is to rest (flat for a flat flue and curved for a circular flue) as shown in
said Figs. 7, 9, 5 and 6.
Or the foot part m¹ attached to the disc or block m is or may be made with
a pivot mx to fit a bearing in the base part m² as shown in Fig. 10. These
igniting discs or blocks m can be easily slided and adjusted to and from the fire
bridge to bring them to such a position as will act most satisfactorily in causing
the unburnt gases that have passed over the fire bridge when mixed with a due
supply of heated air from the hollow box, to ignite, and the capability which the
discs or blocks m have of being swivelled or turned on their vertical axis, admits
of the space for the heated gases between them and the sides of the flue being
adjusted to suit the draught. This swivelling or pivotting arrangement also
admits of the flat sides of the disc or blocks m being turned in the lengthway of
the flue as shown by dotted line in Fig. 7 to make room for a man to pass into and
through the flue.
In Fig. 10 the pivot m* is shown on one side of the centre of the face of the disc
or block so that in case of small flues more space may be given for a man to pass
on one side of the disc or block m when the flat sides are placed in the lengthway
of the flue. These discs or blocks m according to my Invention, besides being
used as igniters near the fire bridge are or may also be used at any other required
parts of the flues to help to mix the passing gases and bring them in closer contact
with the surfaces of, or in the flues to be heated, and those of such discs or blocks
which are placed in parts of the flues where the heated gases have become reduced
in temperature are or may be formed of metal or metal face or protected with fire
resisting or refractory material.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is:
1. In steam boilers or generators constructed with compound flues as before
described, the combination therewith of horizontal return flue tubes extending from
end to end of the boiler placed on each side or over or partly on each side and over
the said compound flues, substantially as hereinbefore described and illustrated by
the Drawings.
2. In steam boiler furnaces the combination of air heating and distributing
arrangements placed at or behind the fire bridge, with an adjustable heater or
igniting disc or block formed of any known or suitable fire resisting or refractory
material, substantially as and for the purpose hereinbefore described and illustrated
by the Drawings.
3. In steam boiler furnaces, the combination of air heating and distributing
arrangements placed at or behind the fire bridge with an igniting disc or block
formed of any known or suitable fire resisting or refractory material, adjustable

page_text: to and from the fire bridge and also on its vertical axis substantially as and for the
purpose herein before described and illustrated by the Drawings.
4. In steam boiler flues the combination therewith of discs or blocks carried by
and arranged to swivel or pivot on a vertical axis on or in a base resting upon the
bottom of the flue, substantially as and for the purpose herein before described and
illustrated by the Drawings.