IMPROVED MEANS AND APPARATUS FOR ECONOMIZING FUEL AND CONSUMING SMOKE. IN STEAM BOILERS AND FURNACES
Year: 1867

page_text: LETTERS PATENT to John Ellison and Joseph Stirk, both of Leeds, in
the County of York, Engineers, for the Invention of "IMPROVED MEANS
AND APPARATUS FOR ECONOMIZING FUEL AND CONSUMING SMOKE. IN STEAM
BOILERS AND FURNACES."
Sealed the 21st April 1868, and dated the 24th October 1867.
PROVISIONAL SPECIFICATION left by the said John Ellison and Joseph
Stirk at the Office of the Commissioners of Patents, with their Petition,
on the 24th October 1867.
We, JOHN ELLISON and JOSEPH STIRK, both of Leeds, in the County of
York, Engineers, do hereby declare the nature of the said Invention for
"IMPROVED MEANS AND APPARATUS FOR ECONOMIZING FUEL AND CONSUMING
SMOKE IN STEAM BOILERS AND FURNACES," to be as follows:-
Our Invention has reference principally to Cornish boilers, though applicable
to other boilers and also furnaces. Taking an old Cornish boiler, for example,
which is fired internally within the flue and behind the bridge, we insert an
archimedean screw composed of metal, cast or wrought, or of any other suitable
substance. This screw may be of nearly the same diameter as the flue itself,

page_text: & may extend from the bridge to the end of the flue. The action resulting
from the use of it is that the flames from the fire after passing the bridge
are conveyed equally over the whole internal surface of the flue, by which
means the water under the flue in the lower part of the boiler becomes heated
(instead of being nearly cold as is the case in ordinary flues), as well as that
surrounding the top and sides. A further result arising from the use of this
screw (the vanes of which are supposed to be solid as well as its centre or
core) is that its vanes becoming heated from the action of the flames the
smoke which would otherwise be emitted into the chimney is consumed, con-
sequently we attain the two points of economizing fuel and consuming smoke.
Modifications of this arrangement which we are about to name give the same
results. In the example above noted the axis of the screw was assumed to be
solid, in some instances, however, we prefer to make it hollow, and we use
such hollow tube either as an air passage from the bridge to the extreme end,
or we make it a water passage communicating at the bridge end with the
lower part of the flue and at the other end with the steam chamber of the
boiler. Also the vanes of the screw we sometimes prefer to make hollow
and of metal, in that case they communicate with the water space of the
boiler, and give additional heating surface for generating steam.
In a new boiler we propose to make the flue itself from the bridge
point to the extreme end of a similar screw formation, thereby gaining the
advantages of increased heating surface and greater or less combustion of
smoke. We may here add that we speak of this arrangement for new boilers
simply because in practice it can hardly be supposed the owners of boilers
will care to take out their old flues, inasmuch as by the first-named arrange-
ment the same results can be attained. In some instances we cause the screw
within the flue to rotate slowly by means of ordinary mechanical appliances,
with the object of aeting as a self-acting flue cleaner.