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

page_text: LETTERS PATENT to Henry Gardner, of the Firm of Robertson,
Brooman, and Company, of 166, Fleet Street, in the City of London,
Patent Agents, for the Invention of "AN IMPROVED MODE OF AND
APPARATUS FOR. VENTILATING FURNACES.". A communication from
abroad by René Gigodot, of the Firm of Gigodot, Laprevote, et
Cie, of Saint Fons, in the Republic of France.
PROVISIONAL SPECIFICATION left by the said Henry Gardner at the
Office of the Commissioners of Patents, with his Petition, on the
17th September 1873.
I, HENRY GARDNER, of the Firm of Robertson, Brooman, and
• Company, of 166, Fleet Street, in the City of London, Patent Agents, do.
hereby declare the nature of the said Invention for "AN IMPROVED MODE
OF AND APPARATUS FOR VENTILATING FURNACES," to be as follows:-
This system of ventilation by injection is founded upon the employ
ment of a mixture of air and superheated steam, in order to render the

page_text: combustion 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 it through a vessel in or to which a series of tubes are arranged
in a flue or smoke way of the furnace, preferably at a short distance 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
its steam. The mixture is thus raised to a very high temperature,
which facilitates the decomposition of the steam, and it is in the
condition most favourable to combustion when it arrives into the
tuyere which distributes it into the fire-space or ash-pit of the furnace.
The arrangements for carrying out this Invention may be very
different, and will vary according to the kinds of boilers or furnaces to
which it may be applied.
I will here describe as an example an arrangement which has answered
well for a boiler of the Cornish stamp with an interior furnace. The
superheater which I apply to this 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 drawn 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 tube can be regulated a
with the greatest precision.

page_text: The injection may be performed as follows:-In this case the injector
consists of a pipe provided at its end with a whistle-shaped ajutage. The
injector tube debouches in the centre of a funnel-shaped opening, which
terminates in a conduit placed in a flue or 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 passed
through the conduit and into the tuyere, which draws it under the fire.
It will be understood that the form and position of the superheater
and injector may be varied according to the sort of boiler and the space
available.
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. This system of ventilation by the injection of super-
heated steam by means of either of the two before described injectors
may be applied to all metallurgical and industrial furnaces, or to the
ventilation of mines, to replace the exhausters, ventilators, and blast
engines at present in use.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Gardner, in the Great Seal Patent Office on
the 17th March 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
GARDNER, of the Firm of Robertson, Brooman, and Company, of 166,
Fleet Street, in the City of London, Patent Agents, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of September, in the
year of our Lord One thousand eight hundred and seventy-three, in
the thirty-seventh year of Her reign, did, for Herself, Her heirs and

page_text: successors, give and grant unto me, the said Henry Gardner, Her
special licence that I, the said Henry Gardner, my executors,
administrators, and assigns, or such others as I, the said Henry
Gardner, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "AN IMPROVED MODE OF AND APPARATUS FOR VENTILATING
FURNACES," communicated to me from abroad by René Gigodot, of the Firm 1
of Gigodot, Laprevote, et Cie, of Saint Fons, in the Republic of France,
upon the condition (amongst others) that I, the said Henry Gardner,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner 1
the same was to be performed, and cause the same to be filed in the
Great Seal Patent Office within six calendar months next and imme-.
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Gardner, do hereby declare
the nature of the said Invention, and in what manner the same is to 2
be performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the Drawings here-
unto annexed, that is to say :-
This system of ventilation by injection is founded upon the employ-
ment of a mixture of air and superheated steam, in order to render the 2
combustion 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 3
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 it through a vessel in or to which a series of tubes are arranged
in a flue or smokeway of the furnace, preferably at a short distance from 3
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

page_text: 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
its steam. The mixture is thus raised to a very high temperature, 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-space or ash-pit of the furnace.
|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
its steam. The mixture is thus raised to a very high temperature, 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-space or ash-pit of the furnace.
The arrangements for carrying out this Invention may be very
different, and will vary according to the kinds of boilers or furnaces to
which it may be applied.
I will here describe as an example and in reference to the annexed
Drawings the arrangement I have adopted for a boiler of the Cornish
stamp with an interior furnace.
Figure 1 is a longitudinal section, and Figure 2 is a horizontal section.
of the arrangement as applied to a Cornish boiler, while in Figures 3, 4,
5, and 6 I show the two arrangements I adopt for the injector. The
superheater which I apply to this system is composed of two collections
of tubes a, a, a, b, b, b, united at one end by two distinct collectors A.
and B, and at the other by another collector C common to both. Upon
the entrance collector A is keyed a pipe d, which brings the saturated
steam drawn from the dome D of the boiler. The exit collector B carries
the ajutage, upon which is fixed a curved tube f, which is united by a
cock socket g with the injector I.
The injector shown at Figures 3 and 4 consists of a cylindrical tube I,
closed by a little plug i, 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 j, fixed in the axis of the tube I by means
of two arms K, K. By screwing the plug i the section of the annular
opening o of the tube can be regulated with the greatest precision.
The injector may also be constructed as shown in Figures 5 and 6.
In this case it consists of a pipe m, provided at its end with a whistle-
shaped ajutage n, in which the steam opening is a very narrow slit a..
The injector tube debouches in the centre of a funnel-shaped opening 1,
which terminates in a conduit L, placed in a flue or a passage arranged
along the boiler outside. This conduit is curved in front of the furnace,
and its branch M forming a tuyere is united to the partition N of the

page_text: ash-pit beneath the bars P.
Thus air is drawn by the jet of superheated
steam proceeding from the tube i, and the mixture of air and steam
passes through the conduit L and into the tuyere M, which leads it
underneath the fire-bars.
ash-pit beneath the bars P. Thus air is drawn by the jet of superheated
steam proceeding from the tube i, and the mixture of air and steam
passes through the conduit L and into the tuyere M, which leads it
underneath the fire-bars.
It will be understood that the form and position of the superheater
and injector may be varied according to the sort of boiler and the space
available.
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. This system of ventilation by the injection of super-
heated steam, by means of either of the two before described injectors,
may be applied to metallurgic and industrial furnaces for all purposes, or
to the ventilation of mines in substitution for the exhausters, ventilators,
and blast engines at present in use.

page_text: And, Fifthly. The conduit tuyere which leads the mixture of air and
superheated steam into the ash-pit beneath the fire-bars, as described
and as shown in Figures 1 and 2 of the accompanying Drawings.
:
In witness whereof, I, the said Henry Gardner, have hereunto set
my hand and seal, this Seventeenth day of March, One thousand
eight hundred and seventy-four.
Witness,
HENRY JAMES GARDNER,
166, Fleet Street,
London.
HENRY GARDNER. (L.S.)