IMPROVEMENTS IN STEAM BOILERS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Joseph Rogers Oldham at the Office
of the Commissioners of Patents on the 1st September 1881.
JOSEPH ROGERS OLDHAM, of Sunderland, in the County of Durham, Consulting
Engineer. "IMPROVEMENTS IN STEAM BOILERS."
My Invention has for its object the increase of effective tube and heating surface,
also better circulation of the water and certain arrangements of furnaces and
combustion chambers in connection with steam boilers, more particularly marine
steam boilers.
My Invention relates to that class of steam boilers in which return tubes or flues
are formed in the bottom or lower portion of the boiler, or sometimes (in case of
flues) under the boiler.
In constructing boilers according to my Invention, I form such boilers with
wing or side furnaces only, devoting the centre and lower portion, or the lower
portion only, or the centre only, to the return tubes or flues, or such return flues
may be brought under the boiler. The furnaces of boilers, according to my
Invention, are constructed in some cases by extending the furnace so as to come
outside, or partly outside, the boiler proper and front tube plate. The extending
furnace may be of wet or partly wet construction; in some cases the tops and sides
only being surrounded by water by means of an external shell round the projecting
portions of furnaces, and air tubes can be brought up through the front smoke box,
hereafter mentioned, to heat the air supplied to the fire grate through the ashpit
outside of the boiler front. From the furnaces I lead nests of tubes or flues to the
back of the boiler, which may be constructed with a wet, or partly wet, or a dry
combustion chamber, extending down to the bottom of the boiler or partly below
the boiler. From the central and lower portion of the combustion chamber I lead
return tubes or flues passing through the lower and central portion of the boiler.
These tubes lead into a front combustion chamber or fire box, which opens into the
moke uptake and chimney. In some cases I divide the back combustion chamber
into two separate chambers, or 1 form two independent chambers, one over the
other, at the back of the boiler, the lower one being the chamber which connects
the furnace tubes or flues with those tubes or flues in the lower portion of the
boiler, and the upper one being used to connect other nests of tubes, being re-return
T

page_text: tubes, which I place in the upper portion of the boiler over the furnaces, and
connect with the front fire box the upper back combustion chamber and the smoke
box respectively.
In the case of double boilers, the boilers may be so placed back to back as to
leave a sufficient space for the back combustion chamber or chambers, and the
front or smoke uptakes may be lead into independent chimneys, or through a bridge
uptake into one chimney common to both.
The essential object of my Invention is the construction of a boiler in which the
products and gases of combustion and flame are led downwards and through return
tubes at the bottom and centre of the boiler so as to heat the water at the coldest
and lowest part, and also to obtain more tube surface and greater and more effective
heating surface, thereby saving coals; also a more general and better circulation of
the water in the boiler, which will greatly lessen the liability of priming and add
considerably to the life of the boiler.
The principle of construction, according to my Invention, can be applied to
existing boilers by removing the lower or central furnace or furnaces from the
boiler by dividing the combustion chamber by a horizontal diaphragm, and
continuing the combustion chamber to the bottom of the boiler and opening it out
into a lower nest of tubes located in the position previously occupied by the central
furnace or furnaces, and providing a front fire box furnace and upper tube arrange-
ment, as previously set forth.