IMPROVEMENTS IN THE CONSTRUCTION OF TUBULAR BOILERS FOR STEAM ENGINES
Year: 1876

page_text: LETTERS PATENT to John Henry Smiles, of Stockton-on-Tees, in the County:
of Durham, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF
TUBULAR BOILERS FOR STEAM ENGINES."
Sealed the 12th April 1876, and dated the 18th January 1876:¯
PROVISIONAL SPECIFICATION left by the said John Henry Smiles at the
Office of the Commissioners of Patents on the 18th January 1876.
JOHN HENRY SMILES, of Stockton-on-Tees, in the County of Durham.
PROVEMENTS IN THE CONSTRUCTION OF TUBULAR BOILERS FOR STEAM ENGINES."
"IM-
This Invention relates to certain improvements in the construction of tubular
boilers for steam engines, whereby a great amount of safety is secured as well as
economy in space and in the consumption of fuel, whilst greater facilities are
afforded for repairing the boiler and cleansing the tubes than by the arrangements
and methods of construction hitherto adopted.
The boiler is constructed, with any desired number of tubes placed within an
external shell, such tubes being respectively closed at both ends. A tank or
reservoir is provided through which the tubes pass, the depth of the former-being
from one-fourth to one-eighth the lengths of the latter; the tubes at one end of the
tank or reservoir projecting only to a small extent beyond the front of the tank or
reservoir. The tank or reservoir is divided into two parts, a diaphragm being
placed transversely therein, and so that the tubes respectively pass through the
same. The front end of each tube is secured by means of a valve cap which is
screwed thereto. In the interior of each tube is placed a tube of smaller diameter
and shorter length, the same being held or retained in position at the front end
thereof by a rod or valve spindle which passes through the before-mentioned valve
cap, and by means of which rod or spindle the tube can be moved backwards or
forwards, there being double valves provided when the rod or spindle is connected
with the tube, one for the purpose of shutting off the smaller tube, and the other to
shut off the larger tube from the tank or reservoir, thus preventing explosion.
The tubes constituting the upper row are employed for the purpose of super-
heating the steam, although they are nearly identical with the tubes below. The
[Price 2d.]

page_text: steam enters at the top of the outer tube, and having passed down the same and up
the smaller tube, makes its exit into the steam pipe at a point as far from the water
as the circumstances of the case will admit.
In order that the flame arising from the combustion of the fuel in the furnace
may act in the most advantageous manner upon the tubes, the latter are not placed
in their rows immediately over each other. but alternately, as will be well
understood (one tube being over the space between the two tubes below it), so that
the flame must of necessity envelope every tube. Each of the smaller tubes is
provided with a supporter at the rear end thereof. The rear ends of the larger
tubes are respectively supported and retained in their proper positions by means of
a cast-iron frame, the apertures in which are of sufficient size to allow of a cast-iron
cap or plug being placed on the end of each tube, and which upon being withdrawn
leaves sufficient space to admit of the insertion of a suitable scraper or brush for the
purpose of cleansing the tube.
Although the foregoing description especially refers to the construction of
horizontal boilers, it must be distinctly understood that this Invention is equally
applicable to the construction of vertical boilers, in which case the tank or reservoir
is made deeper than in the case of horizontal boilers, and one or more tubes being
dispensed with to allow of greater space for the exit of. the flame and products of
combustion. In such cases the frame at the back and the caps or plugs herein-
before referred to are not employed, and the fire is placed underneath the ends of the
tubes.
""
This Invention can also be applied to stationary and marine boilers without any
alterations, except such as will be well understood by persons conversant with such
like machinery.