IMPROVED STEAM BOILER FOR SMALL AND MEDIUM POWERS to be as follows:
Year: 1884

page_text: I, ABEL PIFRE, of Paris, Republic of France, Civil Engineer do hereby declare
the nature of said invention for "IMPROVED STEAM BOILER FOR SMALL AND
MEDIUM POWERS to be as follows:-
"
This invention relates to steam boilers and comprises a steam boiler which is
especially applicable where only a small or medium power is required, the said
boiler being arranged in such a manner that a regular heat is maintained without
any special care having to be taken in supplying the furnace of the boiler with
fuel.
The improved boiler comprises two concentric cylinders between which the water
is contained and which may be connected by means of stays for strengthening the
apparatus and preventing any rupture of the internal cylinder under the influence
of a high pressure. At some distance from the lower part of the boiler is connected
one extremity of a serpentine pipe which descends below the boiler and is then
formed into a flat spiral so as to form a kind of basket which constitutes the grate
of the boiler. The other extremity of the said pipe enters the lower part of the
boiler so that the said pipe is always full of water which circulates therein.
An external casing encloses the boiler, a free space being left between the latter
and the casing. This external casing is closed at its upper part by a disc provided
with a large central perforation the edge of which is raised up, and against the
periphery of which is placed a vertical cylinder fitted by means of a bayonet joint
so as to be easily removed.
Through this vertical cylinder which is closed at its upper part passes a sheet
iron tube which tapers slightly downwards and terminates at some distance from
the upper part of the grate. An annular space is left between the said tapering
tube and the boiler The said tapering tube is connected with the vertical cylinder
in such a manner as to be removable with the same, for cleaning purposes.
The vertical cylinder communicates with the atmosphere by means of a pipe, one
extremity of which may be introduced into an ordinary flue.
The tapering tube is closed by a cover which is sealed by means of a sand
or cinder joint.
Below the grate is placed an ash-pan provided with a door and a pipe which
terminates below the grate and which conveys air from a small fan driven by the
engine supplied with steam from the said boiler.

page_text: This fan which is analogous to that of portable forges, although much smaller,
does not require for its operation more power from the engine than the feed pump
belonging thereto and serves to make up for the insufficiency of the draught in case
there is not a flue sufficiently high to arrange therein the pipe proceeding from the
vertical cylinder. The boiler operates in the following manner, that is to say:
-The space between the two first mentioned cylinders is filled with water up to
a certain height so as to leave sufficient space to form a steam reservoir. The
serpentine pipe forming the grate is thus filled with water, and as its two
extremities are at different levels, a very active circulation takes place as the
water therein is heated The tapering tube is filled with coke or other fuel,
incandescent coke being first introduced in order to start the fire; the cover is
then placed upon the tapering tube.
The heated air traverses the annular space between the inner wall of the boiler
and the tapering tube.
As the air only passes through the coke below the tapering tube this portion
alone is incandescent, the remainder of the coke contained in the said tapering tube
being black. As fast as the fuel is consumed the cinders fall into the ash-pan and
fresh fuel descends from the tapering tube, the fire is therefore self feeding, its
duration depending solely upon the quantity of fuel contained in the tapering tube
which may be made as tall as required. The conical shape of this tube facilitates
the descent of the coke and prevents it from settling without descending.
The heating is very regular as the coke is in successive layers at all the inter-
mediate temperatures between red heat and that of being scarcely warm. As the
fuel descends it passes successively through the different degrees of heat whereby
no loss results from sudden transitions. The durability of the serpentine grate
is ensured by its being constantly full of water even when the water level is
extremely low in the boiler and as the supply of fuel takes place slowly, regularly,
and without any sensible shock, very little wear is caused by the fuel being stirred
upon the grate The boiler is moreover provided with all necessary accessories,
such as valves, a pressure-gauge, and a water-gauge.
When the boiler is over ono horse power it is made quadrangular instead of
cylindrical,
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ALL
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page_text: COMPLETE SPECIFICATION.
I, ABEL PIFRE, of Paris, Republic of France, Engineer, do hereby declare the
nature of my invention for "IMPROVED STEAM BOILER FOR SMALL AND MEDIUM
POWERS" and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to steam boilers especially applicable where only a small
or medium power is required, the said boiler being arranged in such a manner that
a regular heat is maintained without any special care having to be taken in
supplying the furnace with fuel.
In the accompanying drawing:
Figure 1 is a central vertical section of a boiler constructed according to this
invention.
This apparatus comprises two concentric cylinders A, B between which the
water is to be vaporized is contained and which may be connected or not by
means of stays for strengthening the system and preventing any deformation of
the internal cylinder under the influence of the pressure.
The grate of the boiler is formed by a pipe C bent to the form of a serpentine
so as to increase the heating-surface of the apparatus.
The pipe C is connected with the boiler at a certain distance from the bottom,
and descending below the bottom, forms a spiral, several convolutions of which are
arranged so as to form a kind of basket which constitutes the grate proper of the
boiler. The other extremity of the said serpentine enters the bottom of the
boiler so that this serpentine is always full of water which circulates continually
therein.
An external casing D encloses the boiler, a free space being left between the
latter and the casing. This external casing D is closed at its upper part by a
disc F provided with a large central perforation the edge of which is flanged;
against the periphery of which flange is placed a vertical cylinder H fitted by
means of a bayonet-joint so as to be easily removed:
Through this cylinder H which is closed at its upper part passes a sheet iron
tube I which tapers slightly downwards and terminates at some distance from the
upper part of the grate. An annular space is left between the said tapering tube
and the internal wall B of the boiler. The said tapering tube I is connected with
the cylinder H in such a manner as to be removable with the same for cleaning
purposes.
The cylinder H communicates with the atmosphere by means of a pipe K one
extremity of which may be introduced into an ordinary chimney. The tapering
tube I is closed at its upper end by a cover L which is sealed by means of a sand
or cinder joint.

page_text: Below the grate C is placed an ash pan provided with a door M and a pipe N
which terminates below the grate end which conveys air from a small fan driven
by the engine supplied with steam from the said boiler.
This fan which is analogous to that of portable forges, although much smaller,
does not require for its operation more power from the engine than the feed pump
belonging thereto, and serves to make up for the insufficiency of the draught in
case there is not a flue sufficiently high to arrange therein the pipe proceeding from
the vertical cylinder H.
The boiler just described operates in the following manner, that is to say:-
The space between the cylinders A and B is filled with water up to a certain
height so as to leave sufficient steam space. The serpentine pipe forming the grate
is thus filled with water and as its two extremities are at different levels, a very
active circulation takes place as the water therein is heated.
.
The tapering tube I is filled with coke or other non-bituminous fuel, incandescent
coke being first introduced to start the fire, the cover L is then placed upon the
tapering tube to close it.
The air which enters through the ash pan passes through the incandescent coke
upon the grate where it is heated and on its passage to the pipe K traverses the
annular space between the inner wall B of the boiler and the tapering tube I, the
boiler being thus entirely surrounded with hot air.
The serpentine pipe forming the grate being covered all over with incandescent
coke, the evaporation of the water therein takes place very rapidly. As air only
passes through the coke below the tapering tube L this portion alone is incandescent,
the coke contained in the said tapering tube remaining black. As fast as the fuel
is consumed the cinders fall into the ash pan and fresh fuel desoonds from the
tapering tube he fire is therefore self-feeding. its duration depending solely upon
the quantity fuel contained in the tapering tube, which may be made as tall as
required. The onical shape of this tube facilitates the descent of the coke by its
weight and pr its it from settling without descending.
As
The heating is very regular as the coke is in successive layers at all the
intermediate temperatures between red heat and that of being scarcely warm.
the fuel descends it passes successively through the different degrees of heat
whereby no loss results from sudden transitions.
The durability of the serpentine grate is ensured by being constantly full of
water even when the water level is extremely low in the boiler, and as the supply
of fuel takes place slowly, regularly and without any sensible shock very little
wear is caused by the friction of fuel upon the grate.
The boiler is moreover provided with all necessary accessories such as valves, a
pressure-gauge and a water-gauge.
When the boiler is over one horse power it is made quadrangular instead of
cylindrical, all the above mentioned details thereof remaining the same.
It is to be understood that this new system of steam-generator which enables a
regular heating, and which is self-feeding, is applicable to numerous uses, amongst
which I mention particularly steam-engines of the various systems, the heating of
buildings or the like by the circulation of steam or even of hot water, the heating
of cooking apparatus having coils, double bottoms or the like, and also the heating
of air directly or indirectly. Other liquids than water can be introduced into this
generator.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
First. The arrangement at the centre of a boiler, of a movable tube designed to
receive a sufficient supply of fuel to enable the boiler to operate for a long time,
the said fuel consisting preferably of coke or other substance which allows of being
broken into pieces and burning in a similar manner analogous to coke..

page_text: Second. The arrangement of the casings and of the ash-box permitting the
application of a fan driven by the engine, if the draught is insufficient through the
flue or chimney for the escape of the hot gases being too low.
Third. The employment of tubes for producing a rapid circulation of the water,
and arranged either in the form of a serpentine or coil supporting the fuel as shown
in figure 1.
HASELTINE, LAKE & Co.,
For the Applicant