IMPROVEMENTS IN BOILER FURNACES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Andrew Pinkerton at the
Office of the Commissioners of Patents on the 7th February 1883.
ANDREW PINKERTON, of Glasgow, in the County of Lanark, North-Britain,
"IMPROVEMENTS IN BOILER FURNACES,"
This Invention which relates to improvements in boiler furnaces has for its
object to effect more complete combustion of the fuel in such furnaces, and to
prevent formation of smoke therein.
As applied to the furnaces of Cornish, Lancashire, Marine, or other horizontal
flued boilers, or boilers with external furnaces, a large air box or receiver is fitted
behind the ash-pit, the top plate of this box being on a level, or nearly so, with
the fire-grate, which may be of the usual construction. Over the front edge of this
air receiver a bridge is formed, and at some distance beyond the end of the air
box is built a second bridge. At the upper back end of the air box, there is fitted
or formed a nozzle or series of nozzles inclined upwards and towards the front of
the furnace. Through the nozzle or nozzles, heated air from the receiver flows
towards and meets the flame and fire gases in front of the bridge, and by admixture
with the incandescent gases, produces complete combustion. The floating particles
of carbon which would otherwise form smoke, are also consumed by the increased
temperature due to the mixing of the gases with hot air. The flame resulting from
the combustion of the fuel heats the air within the air box or receiver before it
enters the combustion chamber through the nozzles, and the fire bridges are also
highly heated by the flame, so that when the furnace is newly fired, any smoke
that may be carried beyond the air chamber is consumed before passing over the
second bridge.
A movable door is fitted in the front end of the air receiver to regulate the
admission of air to and through it, and this door may be opened and closed froin
the front of the furnace by hand levers, or be opened by hand when firing and
allowed to close automatically as the fuel is consumed. In some cases also, the air
entering the air receiver is previously heated by passing through pipes heated by
the waste products of combustion.
A hinged or other movable door is also fitted in front of the ash box to regulate
the admission of air below the fire-grate and to the air receiver.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Andrew Pinkerton in the Great Seal Patent Office on the
28th July 1883.
ANDREW PINKERTON, of Glasgow, in the county of Lanark, North Britain,
"IMPROVEMENTS IN BOILER FURNACES,"
My said Invention, which relates to improvements in boiler furnaces, has for its
object to effect more complete combustion of the fuel in such furnaces, and to
prevent formation of smoke therein.
My Invention is illustrated by the accompanying Drawings in which Figure 1
is a front elevation, Figure 2 a transverse vertical section, Figure 3 a longitudinal
section and Figure 4 a horizontal section of a double-flued Cornish boiler, fitted
with the improved smoke-consuming furnaces.
Each furnace is provided with the ordinary fire-grate A, and a large air box
or receiver B is fitted behind the ash pit A', the top plate of this box being on a
level, or nearly so, with the firegrate, and its lower edge or bottom being adapted
to fit as nearly as possible the boiler flue A2. Over the front edge of this air-
receiver an ordinary fire-bridge C is formed, and at some distance beyond the end
of the air-box B is built a second bridge D, which is by preference formed as
shown to leave a crescent-like opening d between its upper edge and the inner
periphery of the boiler Blue A2, so that the hot products of combustion may be
directed against the shell of the flue. At the upper back end of the air box B,
there is fitted or formed a large nozzle B¹ (or it might be a series of nozzles)
inclined upwards and directed towards the front of the furnace. Through the
nozzle B¹ or nozzles, heated air from the receiver B (that is, air which has been
partially heated in its passage under the firegrate to the receiver, and more fully
heated within the receiver) flows towards and meets the flame and fire gases in
front of the bridge C, and by admixture with the incandescent gases from the fuel,
produces complete combustion. The floating particles of carbon, which would
otherwise form smoke, are also consumed by the increased temperature due to the
mixing of the gases with hot air. The flame resulting from the combustion of the
fuel heats the air within the air-box or receiver B before it enters the combustion
chamber through the nozzles B¹, and the fire-bridges C, D, are also highly heated
by the flame, so that when the furnace is newly fired smoke that may be carried
beyond the air chamber B, is consumed before passing over the second bridge D.
A hinged or other movable doore E is fitted in the front end of the air receiver B
to regulate the admission of air to and through it, and this door may be opened
and closed from the front of the furnace by hand levers.
Or the door may be
opened by hand when firing, by means of a rod f, which is jointed to it, and be
allowed to close automatically as the fuel is consumed. For this purpose a chain f
is connected to the rod f, and passed round a transverse rod or barrel g, fitted in
front of the furnace, and to which a slow intermittent rotatory motion is imparted
to unwind the chain and close the door gradually. A ratchet and holding pawl g¹
are fitted on the rod g, and the ratchet is lifted one tooth or more at each revolution
of a cam or wiper against the power of a weight H, which is hung by a crank pin
or lever on the transverse rod g. The turning of the ratchet unwinds the chain f¹,
and allows the door E of the receiver B to close slowly, and only after the smoke
produced by firing is thoroughly consumed. The door E is opened previous to
firing by the attendant lifting the pawl from the ratchet, and allowing the weight G
to wind up the chain f¹ on the transverse rod or barrel g. When there are two
furnaces in a boiler, a solid and a hollow rod g are fitted with the ratchets, weights,

page_text: In
and winding barrels (as shown in the Drawing) to actuate each door E inde-
pendently of the other, or separate devices may be applied to each furnace.
some cases the air entering the air-receiver B is previously heated by passing
through pipes heated by the waste products of combustion.
A hinged or other movable door H is also fitted in front of the ash-box A¹, to
regulate the admission of air below the fire-grate and to the air receiver B, and
this door may be made in halves, jointed together as shown, so that it may be
partially opened only if desired.
The air-heating and supplying appliances are made portable, and can be readily
fitted to Lancashire, marine, or other boilers with horizontal flues, or to boilers
with external furnaces.
Having now described the nature of my said Invention, and the manner in which
the same is to be performed, I declare that what I claim as my Invention is,―
First. The arrangement and combination of parts of smoke consuming appliances
for boiler furnaces, substantially as herein described and illustrated.
Second. The combination with a boiler furnace, of the air-heating box, provided
with an inclined nozzle or nozzles fitted behind the fire-bridge and directed
towards the furnace, the box being also provided with a door to regulate the
admission of air, substantially as herein described and illustrated.
Third. The combination with a boiler furnace of the air-heating box B, adapted
to fit the boiler flue, and provided with a discharge nozzle or nozzles and an
air admission door, the fire-bridge C in front or over such box and the bridge D
fitted at some distance behind, substantially as herein described and illustrated.
Fourth. In boiler furnaces the air-heating box B adapted to the boiler flue,
combined with the fire bridge C, and provided with a discharge nozzle or nozzles
and an air-admission door operated automatically by a chain and winding barrel
and ratchet, or by similar devices, substantially as herein described and illustrated.
In witness whereof, I the said Andrew Pinkerton, have hereunto set my hand
and seal this Twentieth day of July, in the year of our Lord, One thousand eight
hundred and eighty three.
DINIZ UDTON
Witness
WALLACE FAIRWEATHER C.E., Fel. Inst. P.A.
Patent Agent
Glasgow.
DINIZ UDTANT
444R