IMPROVEMENTS IN STEAM BOILER FURNACES, AND IN APPARATUS CONNECTED THEREWITH
Year: 1874

page_text: LETTERS PATENT to Richard Hornsby and Jacob Scott, both of the
Spittlegate Iron Works, Grantham, in the County of Lincoln, for
the Invention of "IMPROVEMENTS IN STEAM BOILER FURNACES, AND IN
APPARATUS CONNECTED THEREWITH."
"
Sealed the 20th November 1874, and dated the 25th September 1874.
PROVISIONAL SPECIFICATION left by the said Richard Hornsby and
Jacob Scott at the Office of the Commissioners of Patents, with
their Petition, on the 25th September 1874.
We, RICHARD HORNSBY and JACOB SCOTT, both of the Spittlegate
Iron Works, Grantham, in the County of Lincoln, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN STEAM BOILER
FURNACES, AND IN APPARATUS CONNECTED THEREWITH," to be as follows:-
The object of this Invention is mainly to enable portable steam engines
to burn occasionally straw for fuel, whilst at other times coal or wood.
may be employed.

page_text: We construct the boiler in the ordinary form, and when burning coal
or wood we use the ordinary fire-bars, but for burning straw we remove
these fire-bars and substitute other bars wide apart. We incline these
bars so that their front ends are as low as the bottom of the ash-pit door.
We feed the straw in at the ash-pit doorway through an external hopper &
on to the inclined fire-bars.
By inclining the fire-bars we obtain a much more perfect combustion
than would be obtained with level fire-bars, as the flame from the fresh
straw rises up through that which has already become charred and
completes the combustion.
The straw hopper is provided with a cover, which when. open stands
up in a position to protect the stoker from the heat radiated from the
ordinary fire-door and from the front of the boiler.
To obtain a better combustion and to prevent the escape of sparks we
insert into each of the boiler tubes at the smoke box end a rod having
wings cast upon it. The rod extends eighteen inches or two feet into
the tube, and carries two or three sets of wings. These rods are not
inserted until steam has been raised. They are formed to diminish
greatly the amount of half burnt straw carried through the tubes, and
which is deposited in the smoke box or escapes in an ignited state from
the funnel as sparks.
Sometimes we make the boiler fire-box of unusual depth, and place
the fire-door below the level of the cylindrical barrel of the boiler.
For coal or wood flue horizontal fire-bars are employed, but for
burning straw these are removed and other inclined bars set wider apart
are inserted in lieu of them. The lower ends of these bars are on a level
OB nearly so with the bottom of the doorway, the fire-box of the boiler to
give sufficient room for feeding in the straw. A feed plate or platform
is fixed in front of the fire-door to aid the feeding.
The ash-pit in this case is removed for travelling and secured upon the
feed plate or platform, as the extra depth of the fire-box brings the ash-pit
when in place too close to the ground to be safe on bad roads.
Sometimes we arrange inclined fire-bars to extend only about half way
along the fire-box, from the back to a transverse bar provided to support
them, and which is fixed on the ash pan and extends across the bottom a
of the fire-box.

page_text: We invert through the ash-pit door a curved hopper through which
the straw is fed, so that the straw is delivered from the hopper on to the
surface of the inclined bars.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Richard Hornsby and Jacob Scott in the Great
Seal Patent Office on the 24th March 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, RICHARD
HORNSBY and JACOB SCOTT, both of the Spittlegate Iron Works,
Grantham, in the County of Lincoln, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of September, in the
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Richard Hornsby and Jacob
Scott, Her special license that we, the said Richard Hornsby and Jacob
Scott, our executors, administrators, and assigns, or such others as we,
the said Richard Hornsby and Jacob Scott, our 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 "IMPROVEMENTS IN STEAM BOILER FURNACES,
AND IN APPARATUS CONNECTED THEREWITH," upon the condition (amongst
others) that we, the said Richard Hornsby and Jacob Scott, our
executors or administrators, by an instrument in writing under our or
their hands and seals, or under the hand and seal of one of us or them,
should particularly describo 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,

page_text: NOW KNOW YE, that we, the said Richard Hornsby and Jacob Scott,
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 :-
The object of this Invention is mainly to enable portable steam engines
to burn occasionally straw for fuel, whilst at other times coal or wood
may be employed.
We construct the boiler in the ordinary form, and when burning coal
or wood we use the ordinary fire-bars, but for burning straw we remove
these fire-bars and substitute other bars wide apart. We incline these
bars so that their front ends are as low as the bottom of the ash-pit door-
way. We feed the straw in at the ash-pit doorway on to the inclined
fire-bars.
By inclining the fire-bars we obtain a much more perfect combustion
than would be obtained with level fire-bars, as the flame from the fresh
straw rises up through that which has already become charred and com-
pletes the combustion.
Figure 1 of the annexed Drawings shews in vertical section, and
Figure 2 in horizontal section the fire-box of a boiler arranged for
burning straw in accordance with our Invention. a is the ordinary fire-
door, which when burning straw is kept closed and out of use; b¹, b³, are
the ledges for supporting within the firc-box the ordinary fire-bars for
burning coal or wood; c is the ash-pan, differing but little from an
ordinary ash-pan, except that it is furnished with a ledge c' for supporting
the lower ends of the straw burning fire-bars d, and is furnished with a
flat feed plate c² to facilitate the introduction of the straw fuel into the
furnace through the ash-pan doorway by means of a pitchfork. The
bars d are each of them cast with a portion & of flat dead plate at the
front, and in addition the bars on either side of the fire-box are cast
with deep side plates d³, d². e, e, are cast-iron inclines entering into the
ash-pit doorway a short distance. They serve to guide the straw into the
fire-box.
One of the side bars d is shewn separately at Figures 12, and one of
the inclines e is shewn separately at Figures 13.
Sometimes we arrange inclined fire-bars to extend only about half way
along the fire-box from the back to a transverse bar provided to support

page_text: them, and which is fixed on the ash pan and extends across the bottom
of the fire-box.
We insert through the ash-pit door a curved hopper through which
the straw is fed, so that the straw is delivered from the hopper on to the
surface of the inclined bars.
Figure 3 is a vertical section, and Figure 4 is a horizontal section
shewing this arrangement, and Figures 5 and 6 shew a similar arrange-
ment, but with the form of the parts somewhat varied. In these Figures
the straw hopper is provided with a cover, which when open stands up
in a position to protect the stoker from the heat radiated from the
ordinary fire-door and from the front of the boiler.
Sometimes, when it is desired to burn indifferently coal, or wood, or
straw (changing nothing but the fire-bars) we construct the fire-box of
unusual depth, with the fire-door very low down and extremely wide (in
fact we employ folding doors), and in front of the doors and on a level
with the bottom of the doorway we fix a horizontal feed platform, which
also serves to carry the ash pan when travelling, for in consequence of
the unusual depth of the fire-box it is necessary to remove it from its
place before passing over uneven roads.
Figure 7 is a vertical section, Figure 8 is a front clevation, and
Figure 9 a horizontal section shewing this arrangement. a is the fire-
box;
a' is an aperture in it giving access to the boiler tubes; a², a², are
the folding fire-doors; b, b, are the straw-burning bars; c, the feed
platform; d, a sheet-iron guard or hood around the fire doorway to
protect the workman and the boiler fittings from a rush of flame which
a gust of wind may cause to issue from the fire-box whilst straw is being
burnt; e is the ash-pan. In travelling it is stowed on the platform c
behind the guard or hood d.
To obtain a better combustion and to prevent the escape of sparks we
insert into each of the boiler tubes at the smoke box end a rod having
wings cast upon it. The rod extends eighteen inches or two feet into
the tube, and carries two or three sets of wings. These rods are not
inserted until steam has been raised, and in the lowest tubes we do not
employ them. They are found to diminish greatly the amount of half
burnt straw carried through the tubes, and which is deposited in the
smoke box or escapes in an ignited state from the funnel as sparks.
Figures 10 shew these spark extinguishers,

page_text: We also to a great extent prevent the escape of sparks when burning
straw by giving to the mouth of the blast pipe the form indicated at
Figure 11.
We claim the arrangement of steam boiler furnaces for burning straw,
with inclined fire-bars and with means for feeding the straw along such
fire-bars from the lower end upwards, substantially as described in
respect to Figures 1 to 6 inclusive.
We claim the arrangement of steam boiler furnaces, substantially as
described and shewn in the annexed Drawings.
In witness whereof, we, the said Richard Hornsby and Jacob Scott,
have hereunto set our hands and seals, this Third day of March,
in the year of our Lord One thousand eight hundred and seventy-
five.