AN IMPROVED HOT AIR AP- PARATUS CONNECTED WITH STEAM BOILERS
Year: 1876

page_text: LETTERS PATENT to Charles Pottier, of New Bond Street, in the County of
Middlesex, Gentleman, for the Invention of "AN IMPROVED HOT AIR AP-
PARATUS CONNECTED WITH STEAM BOILERS."
Sealed the 14th October 1876, and dated the 20th April 1876.
PROVISIONAL SPECIFICATION left by the said Charles Pottier at the Office
of the Commissioners of Patents on the 20th April 1876.
CHARLES POTTIER, of New Bond Street, in the County of Middlesex, Gentleman.
"AN IMPROVED HOT AIR APPARATUS CONNECTED WITH STEAM BOILERS."
The object of my Invention is the construction of an improved hot air apparatus
to be applied to steam boilers for utilizing the waste heat therefrom for various
purposes.
To carry out my Invention I place within the tubes or flues of the boiler an
air chamber of cast iron or other suitable material, which I fix at the back of the
fire-grate, and which is used as a bridge. This air chamber communicates with
the outside atmospheric air by means of a pipe or tube passing along one side of
the ash-pit and communicating with an ouside air pipe or tube. At the top part
of the said air chamber or bridge is fixed another pipe or tube of cast or wrought
iron, at the sides of the boiler tube or flue which communicates with another air
chamber at the back of the boiler, To this second air chamber are fixed three
other pipes or tubes taking cold air from the said cold air pipe, and which are
fixed on the sides and bottom flue of the boiler. At the back of the boiler between
it and the chimney is another air chamber, in which a series of pipes or tubes is
fixed, and through these pipes or tubes the excess of heat and smoke from the
combustion passes, thereby producing a large amount of heating surface in the
said air chamber. This air chamber is formed of brickwork, and may also be in
communication with the outside cold air pipe or tube, if required, and the pipes in
communication, and connected with the bottom flue are made by preference of
cast iron, and fixed so as to allow of their being easily swept or replaced when
worn out or damaged. At the top of this air chamber is a pipe for carrying and
distributing the hot air to rooms or other places where hot air is required either
for drying, warming, and heating purposes as the case may be.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
<
said Charles Pottier in the Great Seal Patent Office on the 20th October 1876.
CHARLES POTTIER, of New Bond Street, in the County of Middlesex, Gentleman.
AN IMPROVED HOT AIR APPARATUS CONNECTED WITH STEAM BOILERS."
The object of my Invention is the construction of an improved hot air apparatus
to be applied to steam boilers for utilizing the waste heat therefrom for various
purposes.
To carry out my Invention I place within the tube or tubes of the boiler an air
chamber of cast or wrought iron, which I fix at the back of the fire grate, and
which is used as the bridge, being protected by fire-brick on the front ann top.
This air chamber communicates with the outside atmospheric air by means of a
pipe or tube passing along the ash-pit and communicating with an outside air pipe
or tube. From the top part of the said air chamber or bridge another pipe or tube
of cast or wrought iron passes along the boiler tube or flue and coinmunicates
with another air chamber at the back of the boiler. To this second air chamber
are fixed three other pipes or tubes taking their cold air from the said cold air
pipe, and which are fixed in the side and bottom flues of the boiler. At the back
of the boiler, between it and the chimney, is another and much larger air chamber
in which a series of pipes or tubes is fixed, and through these pipes or tubes the
excess of heat and smoke from the combustion passes, thereby producing a large
amount of heating surface in the said air chamber. This air chamber is formed of
brickwork and may also be in communication with the outside cold air pipe or tube
if required, and the pipes in cominunication and connected with the bottom flue,
are made by preference of cast iron, and fixed so as to allow of their being easily
swept or replaced when worn out or damaged. At the top of this air chamber is
a pipe for carrying and distributing the hot air to rooms or other places where hot
air is required either for drying, warming, or heating purposes, as the case may be.
But to make my Invention better understood I will. now proceed to describe
the same by reference to the accompanying Drawing, in which Figure 1 is a
front clevation of a Cornish boiler with my improved hot air apparatus applied
thereto; Figure 2, longitudinal section of the same; Figure 3 a horizontal section,
and Figure 4 a transverse section of the same. Similar letters of reference are
used in all the Figures to represent similar parts. In the Drawing the details
and some of the parts of the boiler are omitted, only sufficient thereof being shewn
to illustrate my Invention.
a, shews the hollow cast iron bridge forming an air chamber and placed in the
usual position at the back of the fire-grate b; c is the fire-clay covering for pro-
tecting the bridge or air chamber; d is the pipe or tube passing from the front.
of the bridge a along the bottom of the ash-pit g to the pipe e, in front of the
boiler and below the ground level; this pipe e, which I call the cold air pipe is
closed at one end, and the other end is open to allow of the admission of cold air;
is the pipe passing from the top of the hollow bridge a, the other end opening
into the air chamber fixed at the back of the boiler; this air chamber is made
of cast iron, and encloses or forms the back flue of the boiler. The air chamber h
is connected to the cold air pipe e by three pipes, j, k, and ; the pipes jaud k
pass along the side flues m and n of the boiler, and the other pipe passes along
the bottom flue o; A, A, is the large air chamber built of brickwork and placed
between the air chamber and the chimney B; p, p, p, p, are the pipes or tubes
in the chamber A; the lower ends of these pipes 7 fit over collars or rims q in the
perforated plate C, which it placed over an opening D in the bottom of the
chamber A, communicating with the bottom flue o of the boiler; a similar per-
forated plate E is placed over the tops of the tubes p; F is a curved or elbow
pipe or tube passing from the plate E and opening into the chimney B.
thus be seen that the heated air, smoke, and other products of combustion, can pass
from the bottom flue o through the tubes-p into the chimney B, and-leave an
intense heat in the chamber A, A; is a damper in the flue o; s, damper in the
2
It will

page_text: pipe F; t is a pipe for conveying and distributing the heated air from the chamber A;
u is a short pipe for allowing the passage of the heated air from the chamber h
into the chamber A; v is an opening closed by a door which may be made in the
side of the chamber A to allow of the admission of cold air if required.
The action of the improved apparatus is as follows:-Cold air from the cold air
pipe e will pass along the pipe or tube d into the hollow bridge a, and will be
heated and pass along the pipe finto the air chamber h, from which it will escape
at a very high temperature through into the air chamber A; cold air from the
pipe e will also pass along the pipes j, k, and l, and being heated in its passage by
the heat in the flues will also enter and pass from the chamber hat a very high
temperature into the air chamber A, from whence it passes through the pipe t to
the places or rooms where it is required for drying or heating purposes. The air
in the chamber A, as also the air which may be introduced through the opening v,
will also be further heated by contact with the pipes or tubes p, through which
the heated air, smoke, and other products of combustion pass from the flue o,
as.herein-before described.
It will be understood that where two or more boilers are placed side by side
the air chambers and A may be made sufficiently large to extend to all the
boilers. Although my improvements have been shewn and described as applied
to a Cornish boiler they are applicable with equal advantage to other steam
boilers.
Having thus described my Invention, and the best means with which I am
acquainted for carrying the same into effect, I wish it to be understood that I do not
confine myself to the precise details herein laid down, as the same may be varied
without departing from the peculiar character of my Invention, but what I do
claim is
Firstly. The construction and application to steam boilers of the improved hot
air apparatus consisting of a series of tubes and air chambers arranged in the
manner and for the purposes substantially as herein-before described and shewn
in the accompanying Drawing.
Secondly. The employment and method of fixing the vertical tubes in the large
air chamber for finally utilizing the heat from the bottom flue before passing to
the chimney, as herein-before described and represented in the accompanying
Drawing.
In witness whereof, I, the said Charles Pottier, have hereto set my hand and
seal, this Nineteenth day of October, in the year of our Lord One thousand
eight hundred and seventy-siv
Witness,
G. F. REDFERN,
Patent Agent,
4, South Street,
Finsbury.
CH. POTTIER. (L.S.)