IMPROVEMENTS IN STEAM BOILERS
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by John Hutchings Garey and
Alfred William Turner at the Office. of the Commissioners of Patents,
with their Petition, on the 19th July 1873.
We, JOHN HUTCHINGS GAREY, of Birmingham, in the County of
Warwick, Machinist, and ALFRED WILLIAM TURNER, of Birmingham
aforesaid, Draughtsman and Pattern Maker, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN STEAM BOILERS," to be
as follows:-
—
Our Invention consists in constructing and arranging the parts of
steam boilers in the manner herein-after described whereby great rapidity
in the generation of steam is obtained together with great economy of
fuel.
.In constructing a steam boiler according to our Invention we give the
boiler by preference the figure externally of a vertical cylinder.
The boiler proper or water space consists of two concentric hollow
cylinders or shells, one of considerably smaller diameter than the other,
the annular space between the said hollow cylinders or shells being
closed both at top and bottom. The boiler is fixed by preference on the

page_text: top of a cast-iron fire-box, having about the same diameter as the boiler;
within this fire-box are the fire-bars and ash-pit; the said fire-box has a
door or opening for feeding the fuel and admitting air for combustion.
In the cylindrical space of the interior of the boiler is a vertical coil of
tubing, the axis of the said coil of tubing being coincident with the axis 5
of the boiler; the bottom of this coil opens into the bottom of the boiler
proper or water space, and the top of the said coil opens into the top of
the boiler proper; there is thus a free communication between the boiler
proper and the interior of the tubing of the coil, the said coil constituting
an integral part of the boiler, the water standing at the same level both 1
in the boiler proper and in the tubing of the coil.
We prefer to make the coil of tubing of a spiral or tapering figure,
that is of less diameter at top than at bottom.
The flame and heated air from the furnace pass for the most part up
the axis of the coil of tubing described, and owing to the small diameter 1
of the upper part of the said coil the said flame and heated air pass
partly out at the top of the coil and partly pass laterally between the
several convolutions of the coil from the interior to the exterior of the
coil. The said flame and heated air being thus filtered as it were
through a large extent of heat absorbing surface the heat is very
effectually abstracted therefrom and steam generated in proportion.
A series of vertical fire-tubes is arranged at a convenient distance
apart between the outer and inner shells or hollow cylinders of the body
of the boiler or boiler proper, the lower ends of the said fire-tubes opening
into the fire-box, and their upper ends opening into the smoke flue at s
the top of the boiler. A portion of the flame and heated air from the
furnace passes up these tubes and assists in the generation of steam.
Instead of making the coil of tubing of a spiral or tapering figure it
may be of the same diameter throughout; and instead of being circular
in cross section it may be square, hexagonal, octagonal, or other angular
figure in cross section.
Each convolution of the coil, whether circular or angular, may be
made of two or a greater number of pieces, joined together by screw
collars.
Where we make the coil square in cross section we prefer to make
each convolution of four straight pieces of tubing, joined together by
four elbow pieces.

page_text: Besides the connection of the coil of tubing with the body of the boiler
at top and bottom it may be connected therewith at one or more inter-
mediate points.
Instead of fixing one large coil in the axis of the cylindrical space in
the interior of the boiler two or more smaller coils may be employed..