Improved Apparatus for Superheating Steam.
Year: 1895

page_text: Date of Application, 11th Nov., 1895
Complete Specification Left, 31st July, 1896-Accepted, 3rd Oct., 1896
PROVISIONAL SPECIFICATION.
Improved Apparatus for Superheating Steam.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23 Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of the said
invention, (a communication to me from Messrs. Henri Satre et Fils Ainé
of 8 & 9 Quai Rambaud, Lyons, in the Republic of France, Engineers) to be
as follows:
The apparatus constituting the subject of the present application belongs to
that olass of superheaters in which the steam coming from the boiler passes to the
interior of metallic chambers exposed to the heat of the steam boiler furnace itself
or of a special furnace.
It is characterized by a particular mode of construction of the said chambers
and by a special interior arrangement for the circulation of the steam.
The employment of cast iron in the construction of these apparatuses is
dangerous on account of the weak resistance of this metal to the temperatures to
which it is exposed. The communicators have attempted to substitute cast steel.
for the above, but this material corrodes and rapidly wears out on the surface in
contact with the flames. They have therefore devised the covering of this steel
chamber with a coating of cast iron. so as to preserve it from contact with the
flames. Advantage is thus taken of the great resistance of steel against fracture
and of the resistance of cast iron against the action of the fire.
To simplify the chambers thus composed they are formed of a single cylindrical
body or of a series of separate cylindrical bodies, in the interior of each of which
placed an Archimedean screw having a hollow or solid shaft serving to give
a novement of rotation to the steam passing through the superheater, in order
that centrifugal force may project the water, drawn off with the steam, against the
hot sides of the chamber.
The invention is illustrated in the accompanying drawings in which Figure 1
represents the application of a superheater having a single body, above the bridge
of a masonry furnace. The inner envelope A is a cylinder of cast steel closed at
one end, the outer envelope B, of cast iron, is cast around the preceding or applied
thereto in any convenient manner. In the interior is placed a screw C whose
threads or blades exactly fit the cylindrical part and whose hollow shaft is in
communication with the steam conducting tube D. The steam passes therefore
through this hollow shaft to the end of the superheater and returns, following the
helical channel formed by the threads or blades of the screw, into the chamber F,
whence it is delivered by the tube E to the apparatuses in which it is to be utilized.
This arrangement enables the steam inlet and outlet tubes to be placed at the
same end of the superheating chamber, thereby facilitating the installation of
the apparatus.
Figure 2 shows an example of a superheater having two vertical bodies inter-
communicating with each other by a tubular junction G at the lower part. The
construction is the same as in the preceding case, except that the screws C C¹ have
solid shafts, the steam enters at the upper part of one of these bodies through the
tube D, and in descending follows the threads or blades of the screw C, passes into
the other body through the communicating tube G, again rises following the
threads of the screw C₁ and finally escapes by the tube E.

page_text: Any given number of elements or sections thus formed can be connected!
together in series by causing the inlet and outlet tubes D E to communicate with
two main tubes, one of which Di conveys the steam from the boiler, whilst the
other E¹ conveys it away after having been superheated.
These examples are sufficient to clearly illustrate the principle of the invention,
but other arrangements or combinations of the elements or sections above described
may be employed according to the various applications of the invention
These elements or sections may be placed in any convenient part of the furnace
or of the flues of the boiler or even in a special furnace.
Dated November 11th 1895
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.
I, BENJAMIN JOSEPH BARNARD MILLS of 23 Southampton Buildings in the
County of London, Patent Agent, do hereby declare the nature of this invention,
a communication to me from Messrs. Henri Satre et Fils Ainé of 8 and 9 Quai
Ramband, Lyons, in the Republic of France, Engineers, and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement::-
'
The apparatus constituting the subject of the present application belongs to that
class of superheaters in which the steam coming from the boiler passes to the
interior of metallic chambers exposed to the heat of the steam boiler furnace itself
or of a special furnace.
It is characterized by a particular mode of construction of the said chambers
and by a special'interior arrangement for the circulation of the steam.
The employment of cast iron in the construction of these apparatuses is
dangerous on account of the weak resistance of this metal to the temperatures to
which it is exposed. The communicators have attempted to substitute cast steel
for the above, but this material corrodes and rapidly wears out on the surface in
contact with the flames. They have therefore devised the covering of this steel
chauiber with a coating of cast iron so as to preserve it from contact with the
flames. Advantage is thus taken of the great resistance of steel against fracture
and of the resistance of cast iron against the action of the fire.
To simplify the chambers thins composed they are formed of a single cylindrical
body or of a series of separate cylindrical bodies, in the interior of each of which
is placed an Archimedeau screw having a hollow or solid shaft serving to give
a movement of rotation to the steam passing through the superheater, in order
that centrifugal force may project tlie water, drawn off with the steam, against the
hot sides of the chamber.
a
The invention is illustrated in the drawings accompanying my Provisional
Application in which Fig. 1 represents the application of a superheater having
single body, above the bridge of a masonry furnace. The inner envelope A, is a
cylinder of cast steel closed, at one end, the outer envelope B, of cast iron, is cast
around the preceding or applied thereto in any convenient manner. In the interior
is placed a screw C whose threads or blades exactly fit the cylindrical part and
whose hollow shaft is in communication with the steam conducting tube D. The
steam passes therefore through this hollow shaft to the end of the superheater and
returus, following the helical chauuel formed by the threads or blades of the screw,.
into the chamber F, whence it is delivered by the tube E' to the apparatuses in
which it is to be utilized. This arrangement enables the steam inlet and outlet

page_text: tubes to be placed at the same end of the superheating chamber, thereby facilitating
the installation of the apparatus.
Fig. 2 shows an example of a superheater having two vertical bodies inter-
communicating with each other by a tubular junction G at the lower part. The
construction is the same as in the preceding case, except that the screws C. Ct have-
solid shafts, the steam enters at the upper part of one of these bodies through the
tube D and in descending follows the threads or blades of the screw C, passes into.
the other body through the communicating tube G, again rises following the
threads of the sorew C and fiually escapes by the tube E.
Any given number of elements or sections thus formed can be connected together
in series, by causing the inlet and outlet tubes D E to communicate with two main.
tubes, one of which D' conveys the steam from the boiler, whilst the other E¹
conveys it away after having been superheated.
These examples are sufficient to clearly illustrate the principle of the invention,
but other arrangements or combinations of the elements or sections above described
These-
may be employed according to the various applications of the invention.
elements or sections may be placed in any convenient part of the furnace or of the
flues of the boiler, or even in a special furnace.
Having now particularly described and ascertained the nature of the said inven--
tion and in what manner the same is to be performed I declare that what i
claim is :-
1. In apparatus for superheating steam whether heated by the boiler furnace or
by a special furnace, the construction of the superheating chambers of two metals,
namely steel and cast iron, the one, steel, capable of resisting a great pressure.
of steam, being placed in the interior, the other, cast iron, refractory to heat.
and resisting oxidation by the flame, being placed on the exterior, substantially
as herein set forth.
2. In stean superheating apparatus, the application to cylindrical superheating
chambers of a screw having either a hollow or solid shaft, whose threads or blades
touch the interior of the cylinder and thus form a helicoidal channel traversed by
the steam substantially as herein set forth.
3. The improved apparatus for superheating steam, substantially as herein
set forth.
1000
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.