A NEW AND IMPROVED FIRE-POT AND RETORT FOR STOVES, RANGES, AND FURNACES IN WHICH STEAM IS GENERATED AND SUPERHEATED
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by William Ennis at the Office
of the Commissioners of Patents, with his Petition, on the 6th December
1865.
I, WILLIAM ENNIS, of the City, County, and State of New York, do hereby
declare the nature of the said Invention for "A NEW AND IMPROVED FIRE-POT
AND RETORT FOR STOVES, RANGES, AND FURNACES IN WHICH STEAM IS GENERATED
AND SUPERHEATED," to be as follows:-
My Invention consists in a new method of constructing fire-pots and
retorts, by which steam is generated in the pot or retort itself, instead of being
taken from an independent boiler, for the purpose of promoting and aiding
combustion in stoves, ranges, and furnaces. I make fire-pots or retorts
of cast iron, and cast them in sections and hollow segments. The sections
and segments are connected with pipes and bound together with screw bolts,
and the joints are closed with iron filings and red lead in the usual way of
uniting cast-iron surfaces tightly; or they are cast in single pieces in which
are chambers formed by partitions within the several chambers opening into
each other, one of the chambers being a steam generator into which water is
conveyed by means of a pipe, and the others superheating and distributing
chambers, from which last chamber the superheated steam is discharged in
jets through small holes into the fire, which holes are drilled or made in cast-
ing, as herein-after more particularly described.
One essential object of this Invention is the constant protection of the fire-
pot or retort from injury by exposure to an intense and prolonged action' of

page_text: heat. When the fire-pot or retort is supplied with steam from an indepen-
dent boiler, as in the old way, it is exposed to the direct action of the fire
without the protection of water or steam, until steam is raised in the boiler
when the fires are started; and this exposure quickly burns out the iron and
destroys the fire-pot or retort. In my fire-pot or retort the water or steam is
always in it, and thus it is effectually protected against injury by exposure to
an intense and prolonged action of heat.
Another great advantage is that as soon as the fire begins to burn steam is
generated in the fire-pot or retort, and assists materially in promoting the
combustion of the fuel, which is important in all cases in making fires, but
especially useful in getting steam up rapidly in locomotives and steamboats.
Entire control over the supply of steam to a fire is also gained by this method
of generating and applying it, simply by regulating the quantity of water con-
veyed into the fire-pot or retort. It is also much cheaper.
I now proceed to describe more particularly the arrangement and operation
of the fire-pot or retort. It consists, as before stated, of a chamber, forming
a steam generator, a superheating chamber, and a distributing chamber;
within the steam-generating part of the fire-pot or retort is the steam chamber
or boiler. Water is conveyed into this chamber by a pipe connected with
a. water tank or service water pipe, from which the "quantity of water
drawn is regulated by a water feed which supplies it as desired 'as rapidly as
it is converted into steam and discharged into the fire; the water is 'thus kept
nearly at a certain level in the steam chamber. The steam 'passes from the
steam-generating part to the superheating part of the 'fire-pöt 'ör retort
through connecting pipes and through openings in the partitions between "the
chambers. The steam after being superheated next passes through 'connect-
ing pipes into the distributor or discharging chamber 'and is discharged there-
from in small.jets through holes into the fire directly against the ignitel
coals. The connecting pipes are screwed into the castings at one end, and
fitted tightly into corresponding holes at the other end, which are closed with
iron filings and lead in the usual way, when the segments of the fire-pot' or
retort are put together. The segments thus locked together remain firm in
their place when set in a stove or heating furnace. The fire-pots or retorts
may be of any convenient form, round, rectangular, or otherwise.
For a steam boiler furnace I prefer to make the retort the length of 'the'
grate bars and of such thickness as to occupy the space of one or more-bars, 'say,
about 5 to 6 inches when placed in the furnace. I cast it in sections laterally,
the line of division between the upper and lower sections running a little
below the middle of the retort. The upper section is constructed to 'contain.

page_text: the steam-generating chamber and the superheating chamber, and the lower
section forms the outer shell or side of the distributing chamber. The sections
of the retort are drawn tightly together and held in place by screw bolts
which pass up from the bottom of the retort through the distributing chamber
into and through the bottom of the superheating chamber.
In small fire-pots and retorts the discharge holes may be drilled to advan-
tage, but in large and heavy retorts and fire-pots it is much cheaper and
better to form them in the castings by making corresponding channels in the
edges of the sections which are united to each other.