Improvements in Furnaces for the Better Consumption of Smoke.
Year: 1898

page_text: Date of Application, 7th Nov., 1898
Complete Specification Left. 8th Aug. 1899-Accepted. 9th Sept.
1899
PROVISIONAL SPECIFICATION.
Improvements in Furnaces for the Better Consumption of Smoke.
1, WILLIAM ROGER DAWE, 82, Andover Street, City of Sheffield, Manager of
Steel Works, do hereby declare the nature of my invention to be as follows:-
My invention modified to suit the various circumstances of the case is applicable
to boiler furnaces, re-heating furnaces and others.
In carrying out the invention in its application to an ordinary reheating
furnace, for example, I provide the chimney or its flue with a damper or valve
to stop the natural draught when required, and I construct one or more return
flues from the back to the front or thereabouts, preferably using their inside
walls whether of metal or brick to form the sides of the furnace in order that
the gases and smoke passing through these return flues may be kept heated.
These flues open into the furnace over the fire and to cause the smoke and
products of combustion to enter at the back end and pass through the flues,
use one or more steam jets suitably placed so as to produce either a forced or an
induced draught.
I also arrange air inlets into the furnace either with or without steam jets
as preferred, and so situated that the air issuing from them will mix with the
smoke and gases from the flues and so passing through the flame of the fire will
be consumed.
The closed damper will then be opened to allow the natural draught through
the chimney to act, and the steam is shut off from the jets.
Dated the 2nd dow of November 1898
ROBT. F. DRURY, C.P.A.,
Agent for Applicant,
Bank Buildings, George Street, Sheffield.
Improvements in Furnaces for the Better Consumption of Smoke.
1, WILLIAM ROGER DAWE, 82, Andover Street, City of Sheffield, Manager of
Steel Works, do hereby declare the nature of this invention and in what manner
the same has to be performed, to be particularly described and ascertained in and
by the following statement:
My invention, when modified in its details to meet the various circumstances
of the case, is applicable to the furnaces of steam boilers, of reheating furnaces,
and other like furnaces, the object of the invention being the better combustion
of smoke

page_text: In the annexed drawings I have shown its application to a reheating furnace,
in which the principle is clearly set out; similar letters of reference indicate
similar parts in both figures.
Fig. 1, represents a reheating furnace in vertical section.
Fig. 2, plan of same in horizontal sections upon different planes.
In carrying out my invention as shown in the drawings which represent an
ordinary reheating furnace, for example, I provide the chimney C, or its flue
with a damper D, or a valve, or like means by which the natural draught may
be stopped when desired, and I construct one or more return flues from the
back of the furnace to the front or thereabouts, these return flues F, may be
formed in the brickwork of the walls, or may be metal pipes as shown, enclosed
within such brickwork, or with one side exposed to the interior of the furnace.
At the front end of the furnace, I carry the flues upwards to a suitable height
and terminate with an opening F O, into the fireplace, preferably near the top
of the bridge B.
The openings F. O, may be continued through the outer part of the wall, to
permit air to enter from the outside, and such outer openings or air inlets should
have suitable doors or like means for closing same when desired.
In order to facilitate the passage of the smoke and other products of combustion
from the furnace through the return flue F, and so into the flames of the furnace
fire, propose to use jets of steam or compressed air suitably situated, such as J,
so as to produce either a forced or an induced draught as preferred.
Thus when the damper D, or its equivalent valve is elosed, the smoke in the
furnace is drawn into the entrance E, through the flues F, and discharged through
the opening F O, into the fireplace and meets the flames and heated gases passing
over the bridge B, ensuring more perfect combustion.
This circulating action may be varied in its duration as desired or necessary;
the pivotted cover I, is for inspection, and it must be understood that inlets for
air may be constructed through the bridge or in other positions, to feed com-
bustion and to aid in obtaining the desired result.
When the damper D, is raised and the steam or other jets are shut off, natural
draught is at once set up, and the products of combustion pass up the chimney.
The same arrangement may be applied to the furnaces of steam boilers, with
such variations of the details as may be necessary to suit the different styles of
boilers, thus for example in a single flue boiler the return flue may consist of
a metal pipe communicating with the chimney-flue and passing through the boiler
flue to the front of the fire bars where a suitable opening or outlet is provided
in the dead plate for the discharge of the smoke from the return flue, over the
fire.
The valve or cover for this outlet I prefer to connect with the fire door in
such a manner that when the fire door is opened for stoking and the like, the
valve of the outlet will automatically close and vice versa.
In boilers where cross tubes are used in the flues, the return flue or flues may
be carried through or closely underneath, or parallel with the ordinary flues,
either through the water space or not, and so to the fire as before described.
Where a forced draught is used, the return flue or flues may end by the bridge
or underneath the firebars, but in all cases the smoke is conveyed back and sub-
mitted to the action of the fire a second time.
Having now particularly described and ascertained the nature of my invention,
and in what manner the same is to be performed, I declare that what I claim,
is:
-
1 The improvements in furnaces for the better consumption of smoke
generated therein, as herein before described and set forth.
2-In reheating furnaces, steam boiler furnaces, and like furnaces, the arrange-
ment of one or more return flues F, in combination with one or more jets of
steam or compressed air such as J, arranged to intercept and carry back the smoke

page_text: of the furnace, to the fire, for more perfect combustion, substantially as herein-
before described, with reference to the annexed drawings.
1
1000
ROBT. F. DRURY, C.P.A.,
Agent for Applicant,
Bank Buildings, Bank Street, Sheffield.