Improvements in or connected with Furnaces.
Year: 1894

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the latents, &c. Act, 1883) as allowed by
the decision of the Comptroller General of the 21st day of September 1897.
Date of Application, 2nd July, 1894
Complete Specification Left, 10th Oct., 1894-Accepted, 10th Nov.,
1894
Improvements in or connected with Furnaces.
I GEORGE RICHARD STEWARD of 15 Queen Street in the City of London,
Consulting Engineer do hereby declare the nature of this invention to be as
follows:
The object of my invention is to provide furnaces and appliances in connection
therewith whereby smoke is prevented or efficiently consumed, saving of fuel and
prevention of nuisance resulting.
The door I arrange and admit air thereto so that an eddy is caused which partially
arrests the smoke and causes it to efficiently commingle with the air admitted
through the door and this mixture in its passage through the furnace and over the
bridge is met by currents or a series of thin sprays of heated air supplied by a
number of inlets as hereinafter described situated at the bridge and also if
desired between the door and the bridge so that the smoke is mixed with hot
air supplied from both ends of the furnace and also in the intermediate portions
of the furnace if desired and thus the temperature necessary for perfect chemical
combination of the smoke gases and air is maintained during combustion.
According to my invention the inner plate of the door is made to cover the
entrance to the furnace except at the lower edge and is perforated on the three
outer edges, in a line with the edge of furnace opening, with holes say for example
of about one square inch superficial area. The lower edge of door is made to
stand off the dead plate a short distance about say an inch but this may be
perforated instead if desired. I provide slots across the door in a position dependent
in a measure upon the kind of fuel used and of a width governed by the area of
the furnace. I provide in conjunction with the said slots guides in the inside of the
door plate the outlets of which guides are so formed or curved inwards, and back
again, as to direct the incoming air back towards the door, these guides, being
surrounded by a number of small perforations acting in the opposite direction,
produce a strong baffle, or eddy, arresting the progress of the smoke by holding
it in suspension until complete admixture of the smoke gases and air is effected.
An air box or chamber is fixed on the front side of this plate and is perforated
with holes and slots of various sizes.
I preferably construct the bridge in a corrugated form over the surface above
and next to the face of the fire bars thus providing a larger superficial area for the
storage of heat.
The said bridge is hollow and may be made of fire bricks, fire clay or metal with
fire brick facing and preferably with a round nose looking towards the furnace
door.
Just below the line of fire hars I provide an opening to the interior of the bridge

page_text: covered by a valve or door adjustable from the front and through this air is
admitted to the bridge in quantity suitable to the kind of fuel being used in the
furnace.
The air which thus passes through the hollow bridge is admitted into the furnace
through a number of inlet nozzles or slotted projections which I will call conveyors
let into openings in the top of the bridge so as to be removable and these may be
made of crucible fireclay or metal. The front parts of these conveyors are
preferably of V shape for the purpose of spreading out and thinning the gases as
they strike against them.
The back or rear side thereof may also be rounded or corrugated or of V form
it being preferably rounded and made to slope towards the furnace front and in it
are perforations or slots made to run vertically or across the conveyors and by
these thin sprays or currents of heated air are distributed to the whole of the space
between the bridge and crown' of the furnace.
These said conveyors are also a means of storing retaining and giving off intense
heat this being the principal point of combustion of the escaping gases.
I may provide across the furnace a bar or hollow piece which rises above the
general line of fire bars and is perforated at the upper part. There may be one
of these bars or hollow pieces say at about the centre of the length of the furnace
or several may be used in various positions in the length of the furnace. I may
also provide side bars with perforations in which are inserted rising pieces with
perforations at or towards their upper ends preferably in such a position that the
air which rises and issues through each of them is drawn in above the fuel by the
draught of the furnace and impinged against the rising piece next it.
The improvements described will enable small coal or other fuel to be consumed
efficiently and economically without the emission of smoke.
Doted this 2nd low of Tu... 1901
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in or connected with Furnaces.
I, GEORGE RICHARD STEWARD of 15 Queen Street in the City of London,
Consulting Engineer do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
-
Many devices, having for their object the perfect combustion of fuel and the
prevention of smoke, have from time to time been tried with varied but not
complete success; I have therefore invented the pierced fire door to be used with
other air inlets to furnaces, shown in the accompanying drawings and hereinafter
described, to accomplish these objects.
My improved furnace door is provided with air inlets of a design to cause eddies
to form in the currents of air admitted to the furnace which partially arrest the
products of combustion, and in so doing mix with them, and the resulting mixture
in its passage through the furnace passes over a fire-bridge at the end of the furnace
farther from the door, where it is met by other currents of air heated in their
passage through a specially formed fire-bridge; and I further provide a series of
air inlets to the furnace on each of the two sides, so that a further supply of air is
made to mix with the products of combustion or of partial combustion from the
fuel in the furnace.
Drawing Fig. 1 is a longitudinal section of a furnace constructed in accordance

page_text: with my invention; Fig. 2 is a cross-section of the same; and Fig. 3 is an elevation
of my improved furnace door.
The door is made to cover the entrance to the furnace above the fire-bars,
except at its lower edge, and is perforated at the sides and 'top near the edges of
the mouth of the furnace with holes C, C, C, C each of about one square inch in
area. The lower edge of the door is about an inch above the dead-plate; or the
door may be made to come down to the dead-plate and have holes pierced in it just
above the dead-plate. The door has additional openings E, E, E, E, formed in an
air-box attached to it through which air enters the furnace by means of guides F, F,
on the inside of the door; these guides F, F, are curved, the upper one downwards,
and the lower one upwards, and both slightly towards the door itself: the position
of the openings E, E, E, E, may be varied to suit the fuel used in the furnace
The air entering the furnace by the holes C, C, C, C, in conjunction with that
coming from F F, causes an eddy which arrests me progress of the gaseous products
from the fuel until they have been perfectly mixed with the incoming air.
The bridge of the furnace is constructed preferably of a corrugated form on the
fire-bar side H, to provide a larger heating surface in a given sectional area of
furnace than is done by a simple plane. The bridge is formed of fire-bricks, fire-
lumps, or metal with fire-brick or fire-lump lining: it is constructed preferably with
an over-hanging nose on the fire-bar side, and with an air chamber, I, in it, the
lower part of which communicates with the underside of the space below the fire-
bars at J, and the upper end terminates at the top of the bridge. The admission
of air to the air chamber, I, is regulated by a valve or door K, worked by a rod
from the front of the furnace. The upper part of the hot air chamber, I, is covered,
but is provided with outlets L, L, L, which I call "conveyors" constructed of metal
or crucible fire-clay; these outlets have openings M formed in them which face
towards the flue and are shaped so as to present their sides at an angle to the
current of the gases with the object of impeding the latter as little is possible. The
jenings M, may also be horizontal or set at an angle. From the position of the
conveyors L, L, L, in the furnace they become highly heated and the air that
passes through the chamber I, in the bridge and through these conveyors also
becomes highly heated, and is drawn in thin films into the furnace, and mixing
with the current of hot gases from the fuel completes their combustion.
At the two sides of the furnace are provided hollow fire-bars in which are
inserted air distributors P with openings at or towards their upper ends, pre-
ferably in such a position that the air which rises and issues through them is drawn
in above the fuel by the draught of the furnace.
Furnaces provided with the improved fire-door, the fire-bridge, and the side air
inlets as shown and herein described, will burn small coal and other fuel efficiently.
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
1 claim is:
-
1. The combination of furnace-door, fire-bridge, and side air-inlets for furnaces,
as hereinbefore described.
2 The furnace doan
with in intots and autlaka
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