An Improved Device for Equalizing the Forced Draught for Destructor or other Furnaces.
Year: 1894

page_text: Date of Application, 5th Sept., 1894
Complete Specification Left, 23th May, 1895-Accepted, 20th July, 1895
PROVISIONAL SPECIFICATION.
An Improved Device for Equalizing the Forced Draught for
Destructor or other Furnaces.
We ROBERT GOSLING of 37 Walbrook in the City of London E.C. Engineer,
BENJAMIN HOOKER HENRY HOOKER and FREDERICK HOOKER all of Pear
Tree Court Farringdon Road London E.C. Engineers do hereby declare the nature
of this invention to be as follows:-
This our invention relates to an improved device for equalizing the force draught
for destructor or other furnaces and the invention has for its object the promotion
of an uniform combustion of the fuel by a more perfect and equal distribution of
the draught over the area of the fire.
Furnaces of this description are provided with a forced draught which is caused
by a nozzle through which a jet of steam is ejected beneath the furnace the jet of
steam drawing in a current of air through a surrounding vent for promoting the
combustion. The space beneath the fire bars is thus charged with air and vapour
at a pressure and it is found in practice that the pressure is concentrated to a great
extent on the weakest part of the fire which offers the least resistance causing
a more rapid combustion at that point to the detriment of the remainder of the fire
frequently resulting in the fire being blown right through at that point the unconsumed
fuel being carried over into the flue thereby causing a vent while the heat is so
intense as to seriously injure the fire bars.
To overcome this objection we propose to provide the furnace with one or
more air chests each of which consists of a cylindrical or other shaped box closed
at one end and provided with one or more slots or a series of holes on the upper face
thereof. Tbe said chests are placed as near the under side of the fire bars as
practicable and the air is forced into them in the ordinary and well-known manner
by means of an injector of any suitable pattern.
We may use a single chest if desired or a series although we prefer to use
one chest to three fire bars. By this means the air is impinged upon every part
of the fire the draught is more equally distributed and the fuel is uniformly
consumed.
Dated this 29th day of August 1894.
ROBERT GOSLING.
BENJAMIN HOOKER.
HENRY HOOKER.
FREDERICK HOOKER.

page_text: COMPLETE SPECIFICATION:
An Improved Device for Equalizing the Forced Draught for
Destructor or other Furnaces.
We ROBERT GOSLING formerly of 37, Walbrook and now of 73 Queen Victoria
Street in the City of London E.C. and BENJAMIN HOOKER HENRY HOOKER
and FREDERICK HOOKER all of Pear Tree Court Farringdon Road London E.C.
Engineers 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 :—
This invention relates to an improved device for equalizing the forced draught
for destructor or other furnaces, and has for its object the promotion of an uniform
combustion of the fuel by a more perfect and equal distribution of the draught under
the area of the fire.
In other forced draught furnaces, the air is forced in by an injector simply
to the underpart of the grate area which is closed in so as to form a chamber.
The injector usually consists of a nozzle through which a jet of steam is injected
into a vent with an air space surrounding the said nozzle, the jet of steam
forcing in a considerable amount of air to the chamber below the fire grate area.
The space beneath the fire bars is thus charged with air and vapour at a pressure
and it is found causes the air to blow through to a great extent in the weakest
part of the fire and that which offers the least resistance increasing the rapidity of
combustion at that point to the detriment of the remainder of the fire, and frequently
resulting in the fire being blown right through the unconsumed fuel being carried
into the flue thereby causing a vent, while the heat is so intense at that point as to
seriously injure the fire bars.
To overcome these drawbacks we provide the furnace with several air chests each
of which consists of a suitably shaped box preferably closed at one end and provided
with slots or apertures on the face thereof.
These air chests are placed near the under side of the firebars and air is forced
into them in any of the ordinary and well known manners preferably by means of
an injector of a suitable pattern by this means the air impinged upon every part
of the fire the draught is more equally distributed and the fuel is uniformly consumed
thus effecting a large saving in the cost of production of steam and entirely preventing
unconsumed fuel being carried away from the fire.
In order that our invention may be more readily understood reference is made to
the accompanying drawings on which
Fig. 1 is a longitudinal section of a portion of a furnace with my improvements
applied thereto.
Fig. 2 is an elevation of the front of the furnace &
Fig. 3 is a transverse section.
A is the furnace having the usual door (a) for the introduction of the fuel.
Bare the firebars which (as seen in Fig. 3) are placed closely adjacent to each
other only a small space being left between the bars. Beneath the said bars Bare
placed the chests C which are preferably semi-elliptical in cross section and into
the front ends of which 'the steam injectors (c) are introduced. The tops of the
said chests (c) which are preferably ridged longitudinally as shown in Fig. 3 are
perforated with a series of holes and slots through which the air issues in jets
against the under side of the fire.
The injectors (c) are attached to a steam pipe D passing horizontally across the
front of the furnace the said pipe D having a joint at one end as at (e) and a
centre (9) at the other so as to allow of its being rotated and the injector nozzles
withdrawn from the mouths of the chests (C). The front of chests (C) are
supported on a rod (ƒ) which is carried by arms (h) from the centre (i) so that

page_text: the rotation of the said rod (f) about the centres (i) will allow the fore ends of the
chests (C) to be lowered and allow a space for a natural draught for the purpose of
lighting the fires or at other times when a forced draught is not required it also
affords a space for the removal of any fine ash or other debris from the furnace
which may have fallen through the interval of the fire bars and settled on the
upper side of the air chests. The space (I) beneath the chests is preferably
open at the front end as shown but it may if desirable be enclosed by a door or
other means.
Having now particularly described & ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
In a forced draught apparatus for furnaces the combination with the furnace of
a series of air chests beneath the fire bars and seperate therefrom having slots or
holes in the upper face thereof, nozzles introduced into the ends of said chests for
the injection of steam an air space surrounding said nozzles means for raising and
lowering the front ends of said chests, the whole constructed arranged and operating
substantially as described and illustrated.
Dand thin 14th J
1005
ROBERT GOSLING.
B. HOOKER.
F. HOOKER.
H. HOOKER.