IMPROVEMENTS IN UTILIZING THE HUSKS OR SHELLINGS OF GRAIN AS FUEL AND IN FURNACES PLAYED THEREFOR "
Year: 1871

page_text: LETTERS PATENT to Robert Douglas and Lewis Grant, both of
Kirkcaldy, in the County of Fife, North Britain, for the Invention
of "IMPROVEMENTS IN UTILIZING THE HUSKS OR SHELLINGS OF GRAIN AS
FUEL AND IN FURNACES PLAYED THEREFOR
"
PROVISIONAL SPECIFICATION left by the said Robert Douglas and
Lewis Grant at the Office of the Commissioners of Patents, with
their Petition, on the 10th November 1871.
We, ROBERT DOUGLAS and LEWIS GRANT, both of Kirkcaldy, in the
County of Fife, North Britain, do hereby declare the nature of the
said Invention of "IMPROVEMENTS IN UTILIZING THE HUSKS OR SHELLINGS
OF GRAIN AS FUEL, AND IN FURNACES EMPLOYED THEREFOR," to be as follows,
that is to say :-
This Invention has for its object the profitable use of husks or
shellings of grain as fuel, and is more particularly applicable to the

page_text: consumption of the husks or shellings of rice in furnaces for the purpose
of generating steam.
One modification of the apparatus comprises a fire-grate, at the upper
or front end of which the husks are delivered by a screw travelling band
or hopper. This grate has a considerable inclination downwards in the
direction of the draught or current through the furnace, the openings
through the grate being situated either longitudinally, as in the case of
ordinary fire-bars, or transversely, like the bars of a louvre or Venetian
blind, or the bars may be constructed with openings through the body
of each bar, or the air may be admitted through openings of other form 1
or position. Across the lower end of the grate a trough is placed to
receive the ash from the husks. In this trough is a revolving or other
travelling apparatus, which removes the ash so as to prevent it from
choking up the fire or accumulating in the grate.
A fan is or may be used to promote the combustion of the husks in ]
the furnace, movable doors, or valves, or other equivalent appliances
being used to regulate the intensity or direction of the fan blast.
In addition to the back bridge of the furnace one or more tongues are
employed, projecting downwards from the roof to check the draught,
deflect the current of flame, and throw down the ashes.
2
In another modification of the apparatus an auxiliary furnace is used
in conjunction with the husk burning furnace, coal, wood, or other fuel
being used in the auxiliary furnace to assist in the combustion of the
husks, that is to say, the auxiliary furnace may be either a grate bar or
hopper furnace in which coal, or wood, or other similar fuel is burnt in 2
the ordinary manner, and connected by one or more flues or passages
with the husk furnace, so that the heat and combustion is communicated
from the auxiliary furnace to the husk burning furnace.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Douglas and Lewis Grant in the Great 3
Seal Patent Office on the 10th May 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
DOUGLAS and LEWIS GRANT, both of Kirkcaldy, in the County of Fife,
North Britain, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of November, in the
year of our Lord One thousand eight hundred and seventy-one, in the
33rd year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Robert Douglas and Lewis Grant,
Her special license that we, the said Robert Douglas and Lewis Grant,
our executors, administrators, and assigns, or such others as we, the
said Robert Douglas and Lewis Grant, our executors, administrators,
or 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 "IMPROVEMENTS IN UTILIZING THE HUSKS
OR SHELLINGS OF GRAIN AS FUEL, AND IN FURNACES EMPLOYED THEREFOR," upon
the condition (amongst others) that we, the said Robert Douglas and
Lewis Grant, by an instrument in writing under our hands and seals,
should particularly describe and ascertain the nature of the said In-
vention, 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 we, the said Robert Douglas and Lewis Grant,
do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, reference being had to
the accompanying Drawings, and to the letters and figures marked
thereon, that is to say :-
Our said Invention has for its object the profitable use of husks or
shellings of grain as fuel, and is more particularly applicable to the
consumption of the husks or shellings of rice in furnaces for the
of generating steam or for other purposes.
purpose
One modification of the apparatus comprises a fire-grate, at the upper
or front end of which the husks are delivered by a screw revolving
drum, travelling band, or hopper. This grate has a considerable incli-
nation downwards in the direction of the draught or current through
the furnace, the openings through the grate being situated either
longitudinally, as in the case of a louvre or Venetian blind, or the bars
may be constructed with openings through the body of each, or the air

page_text: may be admitted through openings of other form or position. Across
the lower end of the grate a trough is placed to receive the ash from the
husks. In this trough is a revolving or other travelling apparatus
which removes the ash so as to prevent it from choking up the fire or
accumulating in the grate.

page_text: the furnace A a hopper B is situated, into which the husks or shellings
to be burned as fuel in the furnace are delivered, and are thence dis-
charged by the grooved roller O into the mouth or passage D, from
which they are carried into the furnace by a current of air generated by
a blast fan or other means. In lieu of employing the grooved roller C,
a revolving drum, screw, or other similarly suitable contrivance may be
used for effecting the same object. As the shellings or husks are burnt
or consumed in the furnace A, the ash resulting therefrom moves down
the inclined bottom of the furnace towards a trough or receiver E,
situated at its lower end, as shewn at Figures 1 and 3, and the ash is
assisted in its onward and downward movement by a blast or current of
air passed into the interior of the furnace A from a chamber F situated
underneath it through openings or interstices between the fire-bars, and
which openings are more particularly illustrated at a, Figures 4 and 5,
which represent a number of the fire-bars drawn to a larger scale; or
the openings may be formed in the body of the bars themselves, and in
lieu of arranging the bars across the furnace as shewn, the said bars may
be laid longitudinally. At the interior of the trough or receiver E a
screw creeper G is situated, and at each end of the said screw creeper a
valve or door H is placed, as shewn at Figure 3, each of which is
rendered self-closing by means of spiral springs b. Over the valves or
doors H hoods I are placed so as to prevent or modify the rush of cold
air into the trough or receiver E, and thence into the furnace A when
the said valves or doors H are opened. The screw creeper G is rotated
by a belt passed round the step pulley J, on the axis of which a spur
pinion K is situated, and geared into a corresponding spur wheel L
situate on one extremity of the screw creeper, as more particularly
shown at Figures 2 and 3. It is obvious however that various other
arrangements besides that shewn may be adopted for driving the
creeper G. As the ash of the burnt shellings or husks falls into the
trough or receiver E, it is traversed by the screw creeper G towards one
or other of the valves or doors H, and the pressure of the ash on the
valve or door pushes the said valve or door outwards, thereby allowing
of the ash being delivered to the outside of the furnace, and thus the
furnace A is prevented from becoming choked with ash. In order the
more effectually to deflect and throw down the ashes a hanging bridge M,
projecting downwards into the furnace as shewn at Figure 1, is
employed.

page_text: In conjunction with the furnace A it is preferred to employ one or
more auxiliary furnaces (on the Drawings two such furnaces N are
shewn situate at the front end of the furnace A), coal, wood, or other
fuel being used in the furnaces N to assist in the combustion of the
husks or shellings in the furnace A. The flame generated in the
furnaces N is conducted into the main furnace A. through flues or
passages o, shewn at Figure 1 of the Drawings, by which means the
husks or shellings are ignited at the mouth of the passage D before they
pass into the body of the furnace A.
It is also preferred to employ a blast fan, not shown on the Drawings,
to promote the combustion in the furnaces A and N, the current of air
being conducted from the fan into the pipes or passages Q shewn at
Figures 1 and 3. A valve R is situated at the upper extremity of each
pipe or passage Q, as shewn at Figure 1, to regulate the quantity of
blast passing into the furnace. The current of air for promoting com-
bustion in the furnaces N is conducted from the passages Q into
chambers P, and is thence passed into the furnaces N through the
spaces between the fire-bars s, and a portion of the air current is
conducted through passages T into the furnace A at the part marked U
in order to prevent any accumulation of husks or ashes at that part. A
further branch or passage V is formed leading from the lower part of
each passage Q into the chamber F in order to prevent the accumulation
of ashes throughout the remainder of the grate of the furnace A, and to
keep them in motion in a downward direction as herein-before described.
Each of the passages P, T, and V are provided with valves y, as shewn
at Figure 1, to regulate the intensity of the current of air passing
through the said chambers or passages; and the passages Q and P are
also provided with doors W and X, shewn at Figure 2 through the
openings shewn closed, by which access may be obtained to the
passages.
It is to be understood that we do not confine ourselves to apply our
improved furnace to the arrangement of boiler shewn on the Sheet of
Drawings hereunto annexed, as it may with facility be adapted to other
arrangements of boilers for generating steam, or to other purposes for
which heat is required.

page_text: Sixth. The employment of a screw or its equivalent for withdrawing
the ashes or other residuum from the furnace, substantially as herein-
before described and shewn upon the annexed Sheet of Drawings.
In witness whereof, we, the said Robert Douglas and Lewis Grant,
have hereunto set our hands and seals, this Sixth day of May,
One thousand eight hundred and seventy-two.