IMPROVEMENTS IN FURNACES FOR STEAM BOILERS
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the
Office of the Commissioners of Patents, with his Petition, on the
19th February 1872.-A communication from abroad by George
H. Diehl, of Chicago, Illinois, United States of America.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co.,
Patent Agents, Southampton Buildings, London, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN FURNACES FOR
STEAM BOILERS," a communication, to be as follows:-
The present Invention is designed to provide more convenient means
for consuming the smoke in or near the fire-box, and secure a more
perfect combustion of the fuel, than have heretofore existed.
The bottom, the rear part, the sides of the casement of the boiler, the
grate and bridge walls, and the front end of the furnace are all con-
structed similarly to those parts of furnaces now in common use, except
as herein-after mentioned. In the inner longitudinal parts of the case-
ment sides are formed recesses or grooves of suitable size to receive two
hot-air pipes, and have the peripheries of the pipes come about flush with
the inside of the said casements. These pipes contain steam pipes, and

page_text: one of the latter communicates with a dome and receives steam there-
from. The steam so taken from the dome is conveyed to the rear of the
casement, whence by means of a communicating pipe it returns in the
lower steam pipe, and communicates with pipes in chambers placed in
the rear of a fire-box, and near the rear end of the casement. These
chambers concentrate the heat at that point, and contain the hot air
before it passes out at openings herein-after described. The rear chamber
is made the highest to concentrate the heat at two points in the rear of
the fire-box before it escapes.
The steam pipes inside the hot-air pipes are held in place by metal
skirtings or strips. Short conducting pipes are provided through which
the air passes from the lower hot-air pipes into the furnace, and which
surround the steam tubes projecting out from the inner steam pipes.
The position of these tubes and pipes at the sides of the fire-box and
over the grate is such that superheated steam and hot air are made to
strike the flame and intensify the heat, and consequently increase the
combustion.
The unconsumed smoke and gas passing backward to the flues of the
boiler are brought in contact with superheated steam and hot air at two
points before they can escape, viz., at the tops of the chambers where they
are supplied with air and steam in sufficient quantities to produce almost
perfect combustion, and thereby save a large amount of fuel and prevent
the annoyance of smoke. The steam as taken from the boiler is super-
heated by the fire in the furnace before it passes out at the tubes, and
the cold air entering the lower pipes is also heated in the same
manner.
The object of having the hot air pass through the pipes surrounding
the tubes is that the steam and air may combine before coming in
contact with the carbonic acid gas escaping from the coal. The
chambers are made concave on their top parts to cause the escaping
gases to pass through a space of uniform width, so that the said gases will
be uniformly supplied with air and steam.