IMPROVEMENTS IN STEAM BOILERS, MORE ESPECIALLY ADAPTED FOR MARINE PURPOSES
Year: 1877

page_text: LETTERS PATENT to George Arthur Cates, of the City and County of Bristol,
.
and Frederick Haward, of Gracechurch Street, in the City of London, for the
Invention of " IMPROVEMENTS IN STEAM BOILERS, MORE ESPECIALLY ADAPTED
FOR MARINE PURPOSES."
Sealed the 18th January 1878, and dated the 27th October 1877.
PROVISIONAL SPECIFICATION left by the said George Arthur Cates and
Frederick Haward at the Office of the Commissioners of Patents on the 27th
October 1877.
GEORGE ARTHUR CATES, of the City and County of Bristol, and FREDERICK
HAWARD, of Gracechurch Street, in the City of London. " IMPROVEMENTS IN STEAM
BOILERS, MORE ESPECIALLY ADAPTED FOR MARINE PURPOSES."
The objects of this Invention are to improve the construction of the combustion
chamber of steam boilers and thereby reduce the weight of such boilers and of the
water necessary for the same; to lessen, the cost of maintenance by reducing wear
and tear; and to provide greater facility of access for examination and repairs.
With these objects, and taking as an example a single furnace multitubular
cylindrical boiler, with flat ends, of the type now frequently constructed for use in
steamships, we alter the construction of the lower portion of the back end thereof
and that part adjacent to the combustion chamber, by making a large rectangular
recess, which is effected by carrying up the plating vertically from the bottom of
the shell at a point in a vertical line with the back end of the fire-grate, or nearly
so, up to about the same height as the top of the furnace, from which point it is
carried backwards to the extreme end of the boiler, thus forming the rectangular
recess before mentioned.
Such portion of the recess as directly faces the end of the furnace is left open or
cut out in such manner that a straight line drawn from the further edge of the
opening in the horizontal portion of the recess to the lower edge of the opening
in the vertical portion of the same would be at an angle of about 45°.

page_text: Around the edges of and so as to cover the opening in the shell of the boiler, we
fix a removeable casing or door, the back of which slopes in a straight line between
the edges of the recess and at the angle of about 45°, as before mentioned, the two
sides of such door being of such á form, corresponding to the form of the sides of
the recess and the back of the door. Therefore, as seen from the furnace, the back
of the combustion chamber consists of a flat plate sloping upwards and backwards
from the fire bridge at the back of the boiler.
The removeable door may be constructed either of cast or wrought metal, the
inner surface or that exposed to the heat of the fire being covered with fire-brick or
other. refractory material to prevent radiation of heat.
In the case of boilers of more than one furnace, and such furnaces at different
levels, the rectangular recess is not necessarily carried in a straight unbroken line
across the end of the boiler as in the case of a single furnace boiler, or of a boiler
of more than one furnace, but such being at the same levels; but said recess may
be made to correspond with the position of each separate furnace.
By means of this Invention as herein-before set forth, we do away with the large
void space in the combustion chamber, behind and below the fire-bridge, render
unnecessary much heavy plating, as .also that part of the boiler most liable to
obstruction from deposits of solid matter.
Our Invention is applicable to boilers generally, whether flue or multitubular,
with one or more furnaces, and without regard to the external form of the boiler.

page_text: :
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Arthur Cates and Frederick Haward in the Great Seal
Patent Office on the 26th April 1878.
GEORGE ARTHUR CATES; of the City and County of Bristol, and FREDERICK
HAWARD, of Gracechurch Street, in the City of London. "IMPROVEMENTS IN STEAM
BOILERS, MORE ESPECIALLY ADAPTED FOR MARINE PURPOSES."
The objects of this Invention are to improve the construction of the combustion
chamber of steam boilers, and thereby reduce the weight of such boilers, and of
the water necessary for the same; to lessen the cost of maintenance by reducing
wear and tear; and to provide greater facility of access for examination and
repairs.
With these objects, and taking as an example a single furnace multitubular
cylindrical boiler, with flat ends, of the type now frequently constructed for use in
steamships, we alter the construction of the lower portion of the back end
thereof, and that part adjacent to the combustion chamber by making a large
rectangular recess, which is effected by carrying up the plating vertically from the
bottom of the shell at a point in a vertical line with the back end of the fire-grate,
or nearly so, or to about the same height as the top of the furnace, from which point
it is carried backwards to the extreme end of the boiler, thus forming the rect-
angular recess before mentioned...
Such portion of the recess as directly faces the end of the furnace is left open or
cut out in such manner that a straight line drawn from the further edge of the
opening in the horizontal portion of the recess to the lower edge of the opening in
the vertical portion of the same would be at an angle of about 45°.
Around the edges of, and so as to cover the opening in the shell of the boiler,
we fix a removeable casing or door, the back of which slopes in a straight line
between the edges of the recess and at the angle of about 45°, as before mentioned,
the two sides of such door being of such a form corresponding to the form of the
sides of the recess and back of the door. Therefore, as seen from the furnace, the
back of the combustion chamber consists of a flat plate sloping upwards and back-
wards from the fire-bridge at the back of the boiler.
The removeable door may be constructed either of cast or wrought metal, the
inner surface or that exposed to the heat of the fire being covered with fire-
brick or other refractory material to prevent radiation of heat.
In the case of boilers of more than one furnace, and such furnaces being at
different levels, the rectangular recess is not necessarily carried in a straight
unbroken line across the end of the boiler, as in the case of a single furnace boiler,
or of a boiler of more than one furnace, but such being at the same levels; but
such recess may be made to correspond with the position of each separate furnace.
By means of this Invention as herein-before set forth, we do away with the large
void space in the combustion chamber behind and below the fire-bridge, render
unnecessary much heavy plating, as also that part of the boiler most liable to
obstruction from deposits of solid matter.
Our Invention is applicable to boilers generally, whether flue or multitubular,
with one or more furnaces, and without regard to the external form of the boiler.
And in order to explain our said Invention more fully we now proceed to describe
the means by which it may be effected in practice, reference being had to the
illustrative Sheet of Drawing accompanying these presents, and to the numeral
figures and letters of reference marked thereon, as follows:-

page_text: one inch to one foot, adapted for steamships, and as it would appear when con-
structed according to our said Invention.
Fig. 2 represents a transverse and vertical section of the boiler on the line A, B,
at Fig. 1, taken through the combustion chamber herein-after described and referred
to, shewing the improved construction thereof.
:At each of the above-mentioned Figures, similar letters of reference are employed
to denote corresponding parts in so far as such parts appear or can be seen at each
of such said Figures respectivelý.
A, A, marks the shell or case of the boiler to be made of the best boiler plates united
together in the usual manner; B, the chimney; C, furnaces; D, combustion
chamber; E, ash-pit; b, b, water space; c, c, crown or top of the combustion
chamber D. The bottom and ends of this combustion chamber are formed of
hollow plates G, g, so as to cover the opening in the shell of the boiler to which it
may be affixed, by rivetting thereto the flanged parts of the said bottom and ends;
d, d, mark fire-bricks fixed to the said bottom and ends to prevent loss of heat by
radiation, and we would here observe that for the purposes of this Invention we
form the bottom and ends G, g, inclined or sloping as represented at Fig. 1, and to
provide greater facility of access for examination and repairs of the said boiler, we
propose to form the inclined bottom g of the combustion chamber as a removeable
door, which may be made either of cast or wrought metal, lined with fire-bricks
as before stated, and the said door may be securely closed and held. fast in any
suitable manner.
In conclusion we would remark that in adapting our said Invention to multi-
tubular cylindrical boilers in which the said furnaces are at different levels, the
rectangular recess formed by the plates G, g, need not necessarily be carried in a
straight unbroken line across the end of the boiler, as in the case of the boiler
above described and represented, but such said recess may be made to correspond
with the position of each separate furnace as before stated.
our
Having now fully described and set forth the nature and object of said
Invention for "Improvements in Steam Boilers, more especially adapted for Marine
Purposes," and the means by which it may be effected in practice, we hereby declare
our Invention to consist in, and we claim,-
Constructing the combustion chambers of steam boilers generally, whether flue
or multitubular, and without regard to the external form thereof, substantially as
above described with reference to the accompanying Drawing, for the purpose of
reducing the weight of such said boilers and the water necessary to generate the
requisite quantity of steam therein.
Also for lessening the cost of maintenance of steam boilers by reducing the wear
and tear thereof, and for providing greater facilities of access thereto for examination
and repairs than heretofore.
In witness whereof, we, the said George Arthur Cates and Frederick Haward,
have hereunto set our hands and seals, the Twenty-fourth day of April,
in the year of our Lord One thousand eight hundred and seventy-eight.
Witness,
A. C. M. PRINCE,
Office for Patents,
9, Adam Street,
Adelphi.
G. A. CATES. (L.S.)
F. HAWARD, (L.S.)