IMPROVEMENTS
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by George Butler at the Office of the
Commissioners of Patents on the 13th November 1876.
GEORGE BUTLER, of Southwark, in the County of Surrey.
FURNACES."
"IMPROVEMENTS IN
My Invention has for its object the consumption of smoke and the economizing
of fuel in furnaces, and consists in certain improvements to be applied to the front
and door of the furnace, whereby air is automatically admitted simultaneously
with the opening of the door, and caused to pass in a baffled course through suitable
chambers and be discharged in a heated condition into the furnace.
In carrying out my Invention according to one modification I form in the furnace
front over the door a chamber containing plates, which are provided with slots
arranged bafflewise or so as to break joint, whereby the air which is admitted.
through openings in the front is conduced in an indirect course and caused to
impinge against a hood or inclined plate, and thence directed into the furnace..
These openings are fitted with a valve or slide actuated automatically by the hinge
pin of the door in such a manner that when the door is opened for the purpose of
charging the furnace with fuel the valve or slide will be moved automatically so
as to uncover the openings, thereby allowing air to enter the chamber. The furnace
door is fitted on its interior with a series of perforated plates forming chambers,
into which any air which does not pass into the furnace by the outlets from the
upper chamber will enter, and through the perforations of which (arranged
bafflewise) it will be conducted in an indirect course and discharged into the
furnace.
According to another modification I provide an outer casing forming the door,
and fit on its inner side next to the furnace or grating placed vertically but with
its bars arranged in a horizontal direction, and inclined towards the inner side at
an angle of, say, about 45° on the outer side of this grating, at a distance of, say,
about one inch therefrom, I place a screen composed of galvanised iron rods of wire,
through which the air which is admitted through the ends of the outer casing is
caused to pass,-and-thereby-become-heated and rarefied before it is delivered by the
grating into the furnace. This admission of air is regulated in such a manner that
air is only supplied to the furnace when the furnace door is opened for the purpose
of firing by the employment of the arrangement next herein-after described. In
[Priss all

page_text: the interior of the outer casing I mount two flaps on one common vertical hinge
pin situate at about the centre of the casing, so, that both flaps shall be operated
simultaneously in opposite directions, and open from or close against the screen for
the admission of air from the opposite ends of the casing to the screen, or for its
exclusion therefrom, as the case may be. The hinges of the flaps are provided with
lugs to clip or embrace the T end of a T shaped lever, which is mounted on a
centre or fulcrum, and carries at its opposite end a projection, which is operated by
the handle in the act of opening the door so as to close the two flaps to be opened
out simultaneously, as before mentioned, the said flaps being subsequently closed
when required by moving the lever in the reverse direction by the aid of a knob or
"handle on the exterior of the door. It is obvious that the flaps may be operated
through the medium of other moving parts than the handle, say, for example, by
means of the hinge pin in the act of closing the door if required. I propose in
some cases to substitute for the wire screen two semi-gratings similar to the inner
grating, but with the bars arranged in the vertical direction, the inclination of one
set of bars being in the opposite direction to that of the other set of bars, and the
two sets converging towards the centre; or I may use a perforated cast-iron plate
in substitution for the semi-gratings, and for the screen if desired.
According to another modification I fit on the inner side of the outer casing a
grating composed of diagonal segments, the bars of the upper and lower segments
being arranged in one direction, by preference horizontal, and the bars of the end
segments in a direction at right angles to that of the others. The bars of this
segmental grating are inclined, as in the case of the inner grating referred to in
the last modification, the inclination of the bars of the various segments being
however so arranged relatively to each other that there shall be a convergence
towards the centre, and consequently a tendency to the concentration of the air at
that part. On the inner side of this segmental grating, say at about 1/2 an inch
therefrom, I place a network of chains of fine pitch or meshes, through which the
In this
air is caused to pass on its way into the furnace, as before mentioned.
modification I arrange the opening for the introduction of the said air into the
interior of the outer casing at the upper part of such casing, and I control the
admission by means of one or more pivotted flaps (composed by preference of sheet
iron) operated by the handle or otherwise in the act of opening the furnace
door. It is preferred in either case to let the door with its appurtenances bodily
into the furnace for a distance of, say, about 3 inches, in order to utilize the heat to
the utmost extent practicable.
I also propose to actuate the flaps automatically by means of a cataract, that is
to say, a cylinder containing a suitable fluid, say, for example, mercury, operating
upon a piston in such a manner that the fluid shall be admitted to the piston by
the act of opening the furnace door, and that after the door is closed the closure of
the flaps shall be gradually effected by the diminishing resistance consequent on
the escape of the fluid through a small orifice, the size of such orifice being regulated
according to the time which is required to elapse for the consumption of smoke by
the admission of heated air in the manner before mentioned.