AN IMPROVED HOT-AIR FURNACE OR STOVE PROVIDED WITH ARRANGEMENTS TO PREVENT THE HEATING OR SCALING OF ITS FRAMES OR SHELLS, OR WALLS, AND OF ITS TUBING OR PIPES
Year: 1878

page_text: LETTERS PATENT to Henry Conradi, of 8, Lower James Street, Golden Square,
in the County of Middlesex, for the Invention of "AN IMPROVED HOT-AIR
FURNACE OR STOVE PROVIDED WITH ARRANGEMENTS TO PREVENT THE HEATING
OR SCALING OF ITS FRAMES OR SHELLS, OR WALLS, AND OF ITS TUBING OR
PIPES." A communication from abroad by Gustav Raven, of Leipzig, in the
Empire of Germany.
Sealed the 4th October 1878, and dated the 18th April 1878.
PROVISIONAL SPECIFICATION left by the said Henry Conradi at the Office
of the Commissioners of Patents on the 18th April 1878..
HENRY CONRADI, of 8, Lower James Street, Golden Square, in the County of
Middlesex. "AN IMPROVED HOT-AIR FURNACE OR STOVE PROVIDED WITH ARRANGE-
MENTS TO PREVENT THE HEATING OR SCALING OF ITS FRAMES OR SHELLS, OR WALLS,
AND OF ITS TUBING OR PIPES." [A communication from abroad by Gustav Raven,
of Leipzig, in the Empire of Germany.]
The reason of heating by hot air being considered as of not much practical value
lay simply in the former defective design and construction of the hot-air apparatus
having rendered the air unwholesome.
The organic substances contained in the atmosphere burn at the heated frame of
the furnace or stove, and the penetrability of hot iron by gases has also not been
taken into consideration. A great quantity of the carbonic oxyds or other poisonous
gases which develop themselves in a stove passes through the pores of the hot iron
and becomes mixed with the atmosphere of the room breathed by its inhabitants.
In order that the application of the warming and heating apparatus by hot air
be still used the above-mentioned danger has of course to be removed. The present
design and arrangement of the apparatus, as represented in the adjoined Drawings,
removes altogether those defects.
The fuel burns on a grate set in a boiler similar to a locomotive boiler. A is the
fire-box; B, B, the supply pipes. As the Drawing shows, the fire-box, as well as
the supply pipes, are surrounded by a water compartment. A receptacle or

page_text: reservoir C, called the expansion vessel, serves to receive the water as soon as it
expands through the beat." At the top of the vessel is placed the pipe D pierced
with a number of holes like a sieve, from where it goes into the hot-air chamber E
in order to mix there the dry air with the damp, or the vapours of the water, and
to render the air therefore more appropriate for breathing, while two branch
pipes a-a go underneath the grate, so that the excess of damp or water vapours is
carried away through it, avoiding herewith any strong pressure of steam in the
furnace.
A water gauge b, open at its top, communicates at its bottom with the water space
of the expansion vessel in order to observe the level.
The condensed water is carried back by means of any of the usual arrangements,
and in the most cases water conduit pipes are provided. By this arrangement any
heating or scaling of the pipes or tubes is avoided; and in order to prevent it as
much as possible the pipes can be water-jacketted to any required length. The
heat used is hereby not lost, the water serving as means of transmitting the heat,
while the outside shell of the boiler always radiates heat.
In
In many cases the hot water could be used directly for heating purposes by
conveying it and making it circulate in a combined set or system of pipes or tubes
laid out for it, as by the ordinary arrangement of warming by warm water.
such cases the expansion vessel has to be placed at the highest point of the
combined pipe or tube system.
The improvements upon which the claims are principally based consist,-
-
1.. In the surrounding or jacketting of the hot-air furnace or stove and its pipes or
tubing with water or any other appropriate liquid to prevent the heating or scaling
of its frames, shells, or walls, and of its tubes, as above described, and illustrated in
the adjoined Drawings.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Conradi in, the Great Seal Patent Office on the 12th
October 1878.
HENRY CONRADI, of 8, Lower James Street, Golden Square, in the County of
Middlesex. "AN IMPROVED HOT-AIR FURNACE OR STOVE PROVIDED WITH ARRANGE-
MENTS TO PREVENT THE HEATING OR SCALING OF ITS FRAMES OR SHELLS, OR WALLS,
AND OF ITS TUBING OR PIPES." A communication from abroad by Gustav Raven,
of Leipzig, in the Empire of Germany..
The reason of heating by hot air being considered as of not much practical value
lays simply in the former defective design and construction of the hot-air apparatus
having rendered the air unwholesome.
The organic substances contained in the atmosphere burn at the heated frame of
the furnace or stove, and the penetrability of hot iron gases has also not been
taken into consideration. A great quantity of the carbonic oxyds or other poisonous
gases which develop themselves in a stove passes through the pores of the hot iron
and become mixed with the atmosphere of the room breathed by its inhabitants.
In order that the application of the warming and heating apparatus by hot air
can continue to be used the above-mentioned danger must be removed. The present
design and arrangement of the apparatus, as represented in the adjoined Drawings,
removes those defects entirely.
The fuel burns on a grate set in a boiler similar to that of a locomotive. A is
the fire-box; B, B, the supply pipes. As the Drawing shows, the fire-box and the
supply pipes are surrounded by a water compartment. A receptacle or reservoir C,
called the expansion vessel, serves to receive the water as soon as it expands by the
heat.
At the top of the vessel is placed the pipe D pierced with a number of holes
like a sieve, from where it proceeds into the hot-air chamber E in order to mix the
dry air there with the dampness or vapours of the water, thus rendering the air
more appropriate for breathing; while two branch pipes a, a', go underneath the
grate, so that the excess of dampness or water vapours is carried away by it,
avoiding in this manner any strong pressure of steam in the furnace.
In order to observe the level a water gauge b, opened at its top, communicates at
its bottom with the water space of the expansion vessel.
The condensed water is carried back by any of the usual arrangements; water
conduit pipes are in most cases provided. By this arrangement any heating or
scaling of the pipes or tubes is avoided.
The pipes can be water-jacketted to any required length, so as to prevent the
heating or scaling as much as possible. The heat used is thus not lost, the water
serving as means of transmitting the heat, while the outside shell of the boiler
always radiates heat.
In many cases the hot water can be used directly for heating purposes by
conveying it and making it circulate in a combined set or system of pipes or tubes
laid out for it, as by the ordinary arrangement of warmning by hot water. In such
cases the expansion vessel has to be placed at the highest point of the combined
pipe or tube system.
Having thus herein described the nature of the said Invention, and the manner
of performing the same, it will be understood that the improvements upon which
the claims are principally based consist,―
1. In the surrounding or jacketting of the hot-air furnace or stove and its pipes

page_text: or tubing with water or any appropriate liquid to prevent the heating or scaling of
its frames, shells, walls, or tubes, as above described, and illustrated in the adjoined
Drawings.
In witness whereof, I, the said Henry Conradi, have hereunto set my hand
and seal, this Twelfth day of October, in the year of our Lord One thou-
sand eight hundred and seventy-eight.
H. CONRADI. (L.S.)