Improvements in the construction of Furnace Doors.
Year: 1897

page_text: Date of Application, 18th May, 1897-Accepted, 11th Sept.,
1897
COMPLETE SPECIFICATION.
Improvements in the construction of Furnace Doors.
We GEORGE RICHARD STEWARD, of 15 Queen Street, in the City of London,
Consulting Engineer, and THE SMOKELESS INCANDESCENT FURNACE SYNDICATE, LIMITED,
of 49 Queen Victoria Street in the City of London aforesaid, 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:-
The object of this invention is to produce, as far as possible, a smokeless furnace,
attempts to secure which, have been frequently made, and with varying results. To
attain this object, we introduce through the furnace door, air, in such a manner that
it becomes heated before it commingles with the smoke and gases distilled from the
incandescent fuel of the furnace, and such commingling is effected so as to ensure a
more complete combustion than heretofore, of the smoke and gases evolved.
We are aware that many inventors have admitted air to the furnace through the
fire-door, and that the air so admitted has been deflected in various ways; but the
means which we employ for ensuring the heating and commingling of the air with
the gases of combustion, is of such a character as will cause it to produce whirling
streams of heated air, that will act more or less independently of each other, when
first meeting with the gases of combustion, and thereby ensure a more perfect
commingling of the admitted air with the generated vapours of the furnace, than has
heretofore been effected.
In the accompanying drawings:
Fig. 1 shows, in elevation, the inner face of the furnace door, fitted according to
my invention.
Fig. 2 is a sectional plan view taken in the line 1, 2 of Fig. 1; and
Fig. 3 is a vertical section, taken in the line 3-4 of Fig. 1, in the direction of the
arrow.
The furnace door, A, is formed with longitudinal vertical openings a, a*, shown in
dots at Fig. 1, and more clearly in the section, Fig. 2.
These openings are covered by a metal box, B, on the front of the door, having
openings in its front, and in all its sides, to leave free ingress for the air, which will
absorb heat from contact with the metal of the door, before entering the furnace
through the openings a a*. Of these openings, there are two pairs, and each opening
is covered with a hollow metallic projection or air trunk, narked respectively b, b*,
which severally form a curved air passage, about equal in breadth to the length of
the opening which it covers.
These curved air passages are arranged in pairs, with the curves turned inwards,
so that the vents of each pair of curved passages are opposed to each other, but in
different planes. The form of these projections or trunks will consequently be such,
that the curved passages 6*, 6*, will have a radius greater than the curved
passages 6 b. The object of this arrangement is to deliver into the furnace, currents
of air from the passages 6*, b*, that will overlap (so to speak) the currents of air
issuing from the passages b, b. By thus admitting streams of air through the fire-
door, which are heated as before explained, we effect the desired commingling of the
air with the gases of combustion, the air thus admitted, by its whirling action,

page_text: effectually sucking up, as into a vortex, the ascending gases, on their passage to the
furnace bridge.
The fire-door may have other openings for the admission of air below the curved
guides, as shewn at c, c. These openings we cover by deflectors, c¹, c' set at different
angles to the door face, as shewn at Fig. 3, the action of which is to cause the two
streams of air admitted, to impinge the one upon the other, and direct a whirling
stream towards the dead plate, which deflects it towards the fire, without interfering
with the whirling action set up in the main supply.
Figs. 4 and 5 illustrate a modification of the means which we employ for
producing the whirling effect above mentioned. Fig 4. is a view of the inner face
of the door, and Fig. 5 a vertical section of the same, taken on the line 5-6 of
Fig. 4. In this case, the openings in the door, covered by the hollow metallic
projections forming the curved passages, are horizontal, in place of vertical, openings.
There is but one pair of hollow curved projections b, b*, and they are situate over
the middle of the door, and extend nearly from side to side thereof.
In this modification, the like provision is made for causing the streams of air,
which pass out from the curved passages, to overlap the one the other, as they enter
the furnace, and thus produce the whirling action that is found necessary to effect
the intimate mingling of the air with the gases evolved from the fuel. Openings c, c,
provided with deflectors c¹, are made in this door, as in that shewn at Fig. 1, for
the purpose of setting up a whirling action in the air admitted to the lower part of
the fire chamber.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed, we declare that what we
claim is :-
1. The means above described for heating the air, and for creating, in the air
admitted through the fire door of the furnace to the space onto or above the fuel, a
circular or whirling motion, such means consisting of a pair or pairs of curved air
passages formed in or on the door, and having rents opposed to each other, but
situate in different planes, as described.
2. In combination with the curved air passages referred to in Claim 1, the
horizontal openings below such passages, furnished with deflectors set at different
angles to the door face, as described, for the purpose of setting up a whirling motion
in the air admitted through the lower part of the door.
NEWTON & SON,
Agents for the Applicants.