IMPROVEMENTS IN FURNACES
Year: 1870

page_text: LETTERS PATENT to Jacob Geoghegan Willans, of No. 9, Saint
Stephen's Crescent, in the Parish of Paddington, for the Invention
of "IMPROVEMENTS IN FURNACES."
Sealed the 16th June 1871, and dated the 20th December 1870.
PROVISIONAL SPECIFICATION left by the said Jacob Geoghegan
Willans at the Office of the Commissioners of Patents, with his
Petition, on the 20th December 1870.
I, JACOB GEOGHEGAN WILLANS, of No. 9, Saint Stephen's Crescent,
in the Parish of Paddington, do hereby declare the nature of the said
Invention for " IMPROVEMENTS IN FURNACES," to be as follows :-
:-
This Invention has for its object improvements in furnaces, and relates.
especially to the class of furnaces in which fuel is burnt whilst held.
suspended in or intermixed with a current of air.
Powdered fuel is withdrawn at a uniform rate from a hopper or other.
receptacle by means of a screw, and it is caused to fall on to a series of
sieves or other such like obstacles which divide the shower and cause it
to be dispersed over a considerable area, so that as near as may be each

page_text: particle may be separately exposed to the action of a current of air into
which it is dropped. The powdered fuel in the hopper or receptacle is
also supported on sieves or such like impediments to its descent in order
that the weight of the material may not cause the fuel at the lower part
of the hopper or receptacle to agglomerate. The current of air may be
obtained either by means of a fan or air forcing apparatus or by the draught
of a chimney. The air holding the dust fuel in suspension is caused to
pass into a fire chamber containing a fire of coke or other large fuel
The air and dust fuel
which will produce a sufficiently open fire.
enter at the side or top of the chamber, and at the bottom of the
chamber is a receptacle for the slag resulting from the ash of the fuel,
Fluxes may be added to the
which is tapped out from time to time.
fuel in the fire chamber to render the ash more fusible. I avoid the
use of fire-bars at the bottom of the chamber and the introduction
of the current of air through them, for such an arrangement is useless
because the slag is liable to choke the bars and check the draft.
Out of the fire chamber below the level of the fuel it contains the flames,
and heated gases pass to the place where the heat is to be utilised, it
be into the body of a reverberatory furnace, or beneath or through
a steam boiler or otherwise.
may
If desired a blast or current of air may be used to urge the fire in
addition to the mixed blast or current of air and fuel, and air may be
introduced to ignite the gases after their exit from the fire chamber.
In order to drive the fan or air forcing apparatus, if such be used, and
the feed screw for the powdered fuel I employ water turbines or wate
engines. I prefer to provide a separate engine or separate engines a
Th
each furnace so that every furnace may be under separate control.
engines may be supplied from an accumulator or vessel in which wate
is contained under pressure or from a head of water.
In place of or together with powdered fuel I in some cases emplo
tar or other hydrocarbon in a liquid or vaporous form, or other liqui
vaporous or gaseous fuel may be thus used, being carried together wit
the air into the fire chamber.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Jacob Geoghegan Willans in the Great Seal Patent
Office on the 19th June 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JACOB
GEOGHEGAN WILLANS, of No. 9, Saint Stephen's Crescent, in the Parish
of Paddington, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of December, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Jacob Geoghegan Willans, Her special
license that I, the said Jacob Geoghegan Willans, my executors, admi-
nistrators, and assigns, or such others as I, the said Jacob Geoghegan
Willans, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after 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 "IMPROVEMENTS IN FURNACES," upon the condition (amongst others)
that I, the said Jacob Geoghegan Willans, my executors or adminis-
trators, 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 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 immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Jacob Geoghegan Willans, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
This Invention has for its object improvements in furnaces, and
relates especially to the class of furnaces in which fuel is burnt whilst held
suspended in or intermixed with a current of air.
Powdered fuel is withdrawn at a uniform rate from a hopper or other
receptacle by means of a screw, and it is caused to fall on to a series
of sieves or other such like obstacles, which divide the shower and

page_text: As the
cause it to be dispersed over a considerable area, so that as near as
may be, each particle may be separately exposed to the action of a
current of air into which it is dropped. The screw is arranged at the
bottom of the receptacle in which the powdered fuel is contained, and
it is driven at a very uniform speed, so that it may carry the fuel
forward out of the receptacle in constant and proper proportion to the
blast or current of air which simultaneously enters the furnace as
herein-after described. The fuel is delivered by the screw into a close
casing or distributing box and falls down on to the sieves which are
contained in the lower part of this casing or box. Wire sieves of a mesh
three-quarters of an inch wide may be employed, and there may be six
sieves one under the other with spaces of about two inches between
them, they are arranged diagonally or in steps so that the wires of no
two of the sieves are vertically under each other. The powdered fuel
in the hopper or receptacle is also supported on seives or such like
impediments to its descent in order that the weight of the material
may not cause the fuel at the lower part of the hopper or receptacle
to agglomerate. Should the dust owing to moisture or other cause
not descend freely through the hopper in which the sieves or obstructions
are placed a vibratory motion may be given to the hopper.
fuel which is delivered by the screw falls in the distributing box
and after it passes the lowest sieve or such like impediment therein and
being now evenly dispersed it meets a blast or current of air entering the
distributing box from one side. The current of air may be obtained
either by means of a fan or air forcing apparatus, or by the draft of a
chimney. The blast or current escapes from the distributing box by
an opening or tuyere opposite to that by which it enters, and the air
holding the dust fuel in suspension is caused to pass into a fire chamber
containing a fire of coke or other large fuel which will produce a
sufficiently open fire. The air and dust fuel enter at the side or top
of the chamber, by preference at the side, and at the bottom of the
chamber is a receptacle for the slag resulting from the ash of the fuel,
which is tapped out from time to time. The fire chamber I prefer
to construct in the form of a cupola ten feet or more high fitted with
a cover at the top which is opened from time to time to charge
the cupola and closes air-tight. The cupola or fire chamber is two feet
square at and below the tuyere with a hole at the bottom for tapping
off slag. The tuyere is eight or nine inches from the bottom. For a fan
blast a five-inch tuyere may be used, and for a pressure blast a smaller

page_text: tuyere will suffice. In the side opposite the tuyere and twelve inches
above the level of the latter I have an opening two feet wide and one
foot high, through which the ignited dust passes horizontally into the
reverberatory chamber or other place wherein its heat is to be utilized.
Immediately above the said opening I have the wall of the fire chamber
thickened inwards and upwards so as to contract the cupola across to
fifteen inches by two feet. This will lessen the tendency of the coke or
other fuel with which the cupola is charged to fall through the lateral
opening. Fluxes may be added to the fuel in the fire chamber to
render the ash more fusible. It will thus be seen that I avoid tho
use of fire-bars at the bottom of the fire chamber and the introduction
of the current of air through them, for such an arrangement is useless
or at least is subject to the great disadvantage that the slag is liable
to choke the bars and check the draft. Out of the fire chamber below
the level of the fuel it contains the flames and heated gases pass as
already mentioned to the place where the heat is to be utilized; it
may be into the body of a reverberatory furnace or beneath or through
a steam boiler or otherwise.
If desired a blast or current of air may be used to urge the fire in
addition to the mixed blast or current of air and fuel. In this case I
prefer to cause the air blast to enter at a level above the tuyere conveying
the dust, but not at a greater height than the centre of the opening.
More than one tuyere to convey the dust may be used if desired. When
using very fine dust the draught from a chimney will in some cases be
found sufficient without blast. Air may be introduced to ignite the
gases after their exit from the fire chamber.
In order to drive the fan or air forcing apparatus if such be used and
the feed screw for the powdered fuel I employ water turbines or water
engines. I prefer to provide a separate engine or separate engines at each
furnace so that every furnace may be under separate control. The
engines may be supplied from an accumulator or vessel in which water
is contained under pressure or from a head of water.
The use of turbines to drive the air forcing apparatus and the fuel
feeding apparatus admits of their relative speeds being adjusted with
great accuracy by means of the valves which govern the passage of the
water to the turbines. When the adjustment is effected it will remain
constant, and the quantity of air and fuel entering the furnace in a given

page_text: space of time will not vary materially until a change in the adjustment
of the furnace is intentionally made. By the use of turbines also the
employment of shafting passing to a distance to convey motion is avoided,
and shafting and such like apparatus is very inconvenient in connection
with furnaces.
It is not essential that the air forcing apparatus should be worked by
a turbine, as the air can if preferred be supplied at a uniform pressure by
forcing apparatus at a distance from the furnaces. Thus the heat of the
furnace and the nature of the flame is brought fully under control, which
is a point of very great importance.
In place of or together with powdered fuel I in some cases employ tar
or other hydrocarbon in a liquid or vaporous form, or other liquid,
vaporous or gaseous fuel may be thus used, being carried together with
the air into the fire chamber containing the coke or other open fuel.
Having thus described the nature of my said Invention, and the
manner of performing the same, 1 would have it understood that I claim,
the construction of furnaces in such manner that a blast or current of
air in which fuel is held suspended is caused to pass to the chamber or
place where the heat is to be used through, underneath, and amongst
coke or other open fuel contained in a fire chamber, such fire chamber
being closed at the bottom excepting an aperture for the escape of the
slag, substantially as described.
I also claim the use of sieves or similar instruments to distribute the
powdered fuel and prevent it clogging, substantially as described.
I also claim the combination of turbines with the fuel feeding
apparatus of dust fuel furnaces, substantially as described.
In witness whereof, I, the said Jacob Geoghegan Willans, have here-
unto set my hand and seal, this Fifteenth day of June, in the year
of our Lord One thousand eight hundred and seventy-one.
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