AN IMPROVED MODE OF AND APPARATUS FOR VENTILATING FURNACES OF STEAM BOILERS
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by René Gigodot at the Office of
the Commissioners of Patents, with his Petition, on the 19th March
1873.
I, RENÉ GIGODOT, of the Firm of Gigodot, Laprevote et Co., of Rue
de Bearn, No. 1, at Lyons, (France,) do hereby declare the nature of the
said Invention for "AN IMPROVED MODE OF AND APPARATUS FOR VENTILATING
FURNACES OF STEAM BOILERS," to be as follows:-
This system of ventilation injection is founded upon the employment
of a mixture of air and superheated steam in order to render the com-
bustion in the furnaces of steam boilers more perfect, thus adding
greatly to the production of steam without increasing the consumption
of fuel.
The formation of the mixture of air and steam takes place in this
Invention according to the principle of the attraction of fluids by the
aid of an injector of a new and very simple construction, which forms
one of the chief features in the Invention.
Steam taken in the saturated state from the boiler is superheated by
passing through a vessel, in or to which a scries of tubes are arranged
in a flue or smoke way of the furnace, preferably at a short distance

page_text: +
from the fire-bars. From thence it is conveyed by one or more pipes
into an air injector or suction tube, whence it proceeds through a very
narrow annular opening, which puts it into the form of a hollow jet
capable of drawing with it a considerable body of air, which becomes
mingled with the steam. The mixture is raised to a very high tempe- 1
rature, which facilitates the decomposition of the steam; and it is in
the conditions most favourable to combustion when it arrives into the
tuyere, which distributes it into the fire-place or ash-pit of the furnace.
The arrangements for carrying out this Invention may be very
different, and will vary according to the kind of boilers or furnaces to
which it may be applied. I will here describe as an example the
arrangement I have adopted for a boiler of the Cornish type with an
interior furnace.
The superheater which I apply to my system is composed of two
collections of tubes united at one end by two distinct collectors, and at
the other end by another collector common to both. Upon the entrance
collector is keyed a pipe, which brings the saturated steam down from
the dome of the boiler. The exit collector carries the ajutage, upon
which is fixed a curved tube, which is united by a cock socket with the
injector.
The injector consists of a cylindrical tube closed by a little plug,
which is formed like a conical valve with a nut head at its top. It is
pierced with a threaded hole, which permits of its being screwed upon a
screw fixed in the axis of the tube by means of two arms. By screwing
the plug the section of the annular opening of the tubes can be regulated
with the greatest precision.
The injector tube debouches into the centre of a funnel-shaped
opening, which terminates in a conduit placed in the flue of a passage
arranged along the length of the boiler outside. This conduit is curved
in front of the furnace, and its branch forming a tuyere is united to the
partition of the ash-pit beneath the bars. Thus air is drawn by the jet
of superheated steam proceeding from the tube, and the mixture of air
and steam passes through the conduit and into the tuyere, which throws
it under the fire..
It will be understood that the form and position of the superheater

page_text: In order to avoid length in the apparatus several jets may be
employed, each in a shorter conduit of smaller diameter. The jets in
certain cases may be full; when they are annular the injectors can be
arranged so as to provoke a draught of the exterior air; and the
injection may be continuous or intermittent at will, according to the
nature of the fuel consumed in the furnace, to which the system may be
applied.