IMPROVEMENTS IN FURNACE GRATES AND CASINGS
Year: 1867

page_text: LETTERS PATENT to Janies Hall, of Barrhead, in the County of Renfrew,
North Britain, for the Invention of "IMPROVEMENTS IN FURNACE GRATES
AND CASINGS." A communication from abroad by Robert Loudon
Walker, residing at Globe Village, Massachusetts, United States of
America.
Sealed the 16th June 1868, and dated the 18th December 1867.
PROVISIONAL SPECIFICATION left by the said James Hall at the Office
of the Commissioners of Patents, with his Petition, on the 18th December
1867.
I, JAMES HALL, of Barrhead, in the County of Renfrew, North Britain, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
FURNACE GRATES AND CASINGS," which Invention has been communicated to me
from abread by Robert Loudon Walker, residing at Globe Village, Massa-
chusetts, United States of America, to be as follows, that is to say:
This Invention relates to furnace grates and casings of the kind in which
water is present internally for the purpose of preventing the injurious action
of the heat of the fire thereon; and it consists, firstly, in making the grate
with a water passage into and through its middle bar, and with two serpentine
passages leading from one end of such bar in opposite directions, and through
the other bars composing the grate or section of grate; secondly, in making
the ends of tho two serpentine passages lead into the opposite ends of a
transverse passage, having the discharge passage or a passage leading to a

page_text: boiler at its middle and diametrically opposite to the inlet passage into the
middle bar, which allows of the grate being set on journals; thirdly, in
making the tops of the hollow bars composing the grate of a bevilled or
trapezoidal form; fourthly, in making the casings or sides of the furnace
chamber or fire-box with spaces for water, and with elongated air passages
crossing such spaces, which air passages combined with stays serve to
strengthen the casings and at the same time to distribute the currents of
water in the best manner throughout the casings; and, fifthly, in combining
the grate and casings and putting the water passages of the grate in com-
munication with the water spaces of the casings, so that the water will pass
first through the grate and then through the casings. The advantage of
causing the water to enter the middle grate bar and then branch off by two
separate courses is, that the water will not be too much heated as it would be
if it were caused to pass from the first to the last bar in one entire serpentine
In the casings however the water entering at the bottom from the
grate in a heated state will in most cases be converted into steam on
approaching the top. The outlets from the casings are therefore made at the
top and lead into the steam space of the boiler if the furnace is adapted to a
boiler; or the steam may be led away from the casings by special independent
pipes for any useful purpose. The surfaces of the casings are by preference
corrugated in order to present an increased heating surface.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Hall in the Great Seal Patent Office on the 17th
June 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HALL, of Bart head, in the County of Renfrew, North Britain, send
greeting.
WHEREAS IIer most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of December, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said James Hall, Her special licence that I, the said James Hall,
my executors, administrators, and assigns, or such others as I, the said
James Hall, 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,

page_text: exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
FURNACE GRATES AND CASINGS," (a communication to me from abroad by.
Robert Loudon Walker, residing at Globe Village, Massachusetts, United
States of America,) upon the condition (amongst others) that I, the said
James Hall, 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
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 James Hall, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following.
statement in writing, reference being had to the accompanying Drawings, that
is to say:
The said Invention relates to furnace grates and casings of the kind in
which water is present internally for the purpose of preventing the injurious
action of the heat of the fire thereon; and it consists, firstly, in making the
grate with a water passage into and through its middle bar, and with two
serpentine passages leading from one end of such bar in opposite directions,
and through the other bars composing the grate or section of grate; secondly,
in making the ends of the two serpentine passages lead into the opposite ends
of a transverse passage, having the discharge passage or a passage leading to a
boiler at its middle and diametrically opposite to the inlet passage into the
middle bar, which allows of the grate being set on journals; thirdly, in
making the tops of the bollow bars composing the grate of a bevilled or
trapezoidal form; fourthly, in making the casings or sides of the furnace
chamber or fire-box with spaces for water, and with elongated air passages
crossing such spaces, which air passages (combined with stays if necessary)
serve to strengthen the casing and at the same time to distribute the currents
of water in the best manner throughout the casings; and, fifthly, in combining
the grate and casings and putting the water passages of the grate in com-
munication with the water spaces of the casings, so that the water will pass
first through the grate and then through the casings.
And in order that the said Invention and the manuer of performing the
same may be properly understood, I have hereunto appended a Sheet of
explanatory Drawings to be herein-after referred to and representing a steam
boiler furnace as constructed with the improved grate and casings.

page_text: Figure 1 is a longitudinal vertical section of the boiler and furnace;
Figure 2 is a transverse vertical section; and Figure 3 is a horizontal section
of the grate. The same reference numerals are used to mark the same parts
in all the Figures.
In Figure 1 the section is supposed to be taken through the middle bar 1
of the grate, and the water from the feed pump enters the front or outer end
of this bar by the pipe 2. At the inner end the passage through the middle
bar 1 communicates with the bars 3, 4, on each side of it; these at their
front ends communicate with the next bars 5, 6, and the two passages are
continued backwards and forwards successively through the bars 7, 9, on one
side, and 8, 10, on the other. The bars forming a set are cast in one piece
with the ends of the passages open, so that the cores can be easily supported
in the mould and as easily withdrawn afterwards. The ends are subsequently
closed by plates 11, 12, which are bolted on, the joint surfaces being
previously ground true so as to form tight joints without cement. When the
size of the furnace renders it desirable the bars may be cast in two or three
separate sets or sections; and each section may be formed with separate inlets
and outlets for the water, or the passage of one section may be made to com-
municate with that of the next by flanged elbow branches projecting down
from the end of each and bolted together, the joint surfaces being previously
ground together. The tops of the bars 1, 3, 4, &c., are made of a bevilled
or trapezoidal form, as shown in Figure 2, in order to prevent ashes from
accumulating on them, and to direct the fuel and cinders into the spaces
between the bars. The passages in the extreme bars 9, 10, at the sides
communicate by pipes 13 which pass along the flue 14 with the back end of
the boiler 15, and by these communications the feed water will pass into the
boiler, whilst they will insure the grates being always full of water when
there is any in the boiler even when the feed pump is not working. The
passages of the side bars 9, 10, also communicate at their inner ends with the
cast-iron casings 16, 17, which line the sides of the furnace. These casings
are cast with bollow spaces, as shown (the cores forming which are removed
through holes which are afterwards plugged), and with passages 18 for the
entrance of air, and the sides of which also serve to strengthen the casings.
Both the external and the internal surfaces of the casings are corrugated to
increase the heating surface. Steam pipes 19 are fitted to the tops of the
easings 16, 17, and communicate with the top of the boiler 15, so that any
steam forming in the casings may find its way into the boiler steam space.
Pipes 20 are fitted to the bottoms of the casings at their front ends to serve
either for blowing off or for feed inlets. When the grate is used without

page_text: having the casings 16, 17, combined with it, it may be made so that it can be
mounted on journals by adding a hollow bar at the inner end at right angles
to the other bars, with its ends communicating with the inner ends of the side
bars 9, 10, and with a pipe attachment at its middle. The various parts are
fixed together by screw bolts, all the water joints subjected to the direct heat
of the fire being fitted together by grinding, and so as to be tight without
cement.
The advantage of causing the water to enter the middle grate bar 1, as
herein-before described, and then branch off by two separate courses, is that
the water will not be too much heated as it would be if it were caused to pass
from the first to the last bar in one entire serpentine course. In the casings
16, 17, however, the water entering at the bottom from the grate in a heated
state, will in most cases be converted into steam on approaching the top.
The outlets 19 from the casings are therefore made at the top and lead into
the steam space of the boiler if the furnace is adapted to a boiler; or the
steam may be led away from the casings 16, 17, by special independent
pipes for any useful purpose.
Having thus particularly described the said Invention, and the manner in
which the same is to be performed, I have to state that the Inventor does not
restrict himself to the precise details herein described or delineated, but that
what I claim as the Invention secured to me by the herein-before in part
recited Letters Patent is, the constructing and arranging or combining
together of the parts of furnace grates and casings, substantially in the
improved manner herein-before described.
In witness whereof I, the said James Hall, have hereunto set my hand
and seal, this Sixteenth day of June, in the year of our Lord One
thousand eight hundred and sixty-eight.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JAMES HALL. (L.B.)
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