IMPROVEMENTS IN SUPERHEATING STEAM
Year: 1856

page_text: LETTER'S PATENT to John Darlington, of No. 36, Cannon Street, in the
City of London, for the Invention of "IMPROVEMENTS IN SUPERHEATING
STEAM." A communication from Gustave Adolphe Hirn, of Colmar, Haut
Rhine, in the Empire of France.
Sealed the 6th February 1857, and dated the 9th August 1856.
PROVISIONAL SPECIFICATION left by the said John Darlington at
the Office of the Commissioners of. Patents, with his Petition, on the
9th August 1856.
I, JOHN DARLINGTON, of No. 36, Cannon Street, London, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN SUPERHEATING STEAM,"
"a communication from Gustave Adolphe Hirn, of Colmar, Haut Rhine, in
the Empire of France," (a foreigner residing abroad,) to be as follows:-
The Invention, communicated to me, consists in passing the steam generated
in the boiler of a stationary locomotive or marine engine through a pipe or a
series of pipes, placed horizontally or otherwise, and causing the heat from the
furnace, after leaving the boiler and before escaping in the usual way by the
chimney, to heat the aforesaid pipe or pipes, and thereby to superheat the
steam contained therein.
The apparatus may be placed so that the heat, after passing under or partly
round the boiler, shall come in contact with it, and then return to the boiler;

page_text: or it may be situated, as described above, in such a manner as to receive the
heat after leaving the boiler.
The apparatus is so constructed and placed as to render its use optional,
and the degree of heat supplied to it may also be regulated as occasion may
require.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Darlington.in the Great Seal Patent Office on the
6th February 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DARLINGTON, of No. 36, Cannon Street, in the City of London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of August, in the year of our Lord One
thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors; give, and grant unto me, the
said John Darlington, Her special licence that I, the said John Darlington,
my executors, administrators, and assigns, or such others as I, the said John
Darlington, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN SUPER-
HEATING STEAM," a communication from Gustave Adolphe Hirn, of Colmar,
Haut Rhine, in the Empire of France, upon the condition (amongst others)
that I, the said John Darlington, iný executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent....
NOW KNOW YE, that I, the said John Darlingon; do. hereby declare
the nature of my said Invention, and-in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being made to the Drawings illustrating my
Invention, and to the figures and letters marked-thereon, that is to say:
My improvements in superheating steam are applicable to stationary

page_text: engines, locomotive engines, marine engines, or to any other description of
engine to which steam is applied as a motive power; but in describing my
Invention I shall consider it only in its relation to stationary engines.
Fig. 1, on the accompanying Sheet of Drawings, represents a cross section
of my apparatus for superheating steam, and the heating chamber in which
it is placed. It also shows part of the furnace and boiler belonging to an
ordinary stationary engine. Fig. 2 is a longitudinal section of the apparatus
(and of the heating chamber; this section is taken through the line A, B, on
Fig. 1. Fig. 3 is a plan of the apparatus. Fig. 4 is a cross section of the
water chambers, marked X, shewing the valves which regulate the degree of
heat to be admitted into the heating chamber; this section is taken on the
line C, D, Fig. 1.
The steam, when it leaves the boiler E, descends by the pipe F, and cir-
culates through the tubes, marked G, which are placed horizontally, as shewn
in Figs. 1 and 2; it then ascends through the pipe H and proceeds directly
to the cylinder of the engine. The extent of heating surface, represented by
the tubes.G, should be in proportion to the power of the engine employed.
.
The flame and heated air, instead of passing immediately from under the
boiler into the flues, are first directed through the passages I and J to the
bottom of the heating chamber K, in which are placed the tubes G. These
tubes are so arranged as to be exposed in the most direct manner to the
influence of the heat, When they have mounted above the tubes G, the
flame and heated air pass through the passage L at the top of the heating
chamber K, and enter the flues round the boiler. The course of the flame
and heated air from the furnace to the flues of the boiler is shown by arrows.
I do not confine myself to any particular arrangement of tubing, or even to
tubing at all, as the steam may be superheated in a single chamber or in many
chambers, of any form, and placed in a variety of positions; but I prefer the
arrangement of tubing as shown.
I propose to guide the flame and heated air from under the water chambers
X into the heating chamber K by means of what I term regulator valves,
which are shown in Fig. 4, and are marked M. These valves serve not only to
turn the flame and heated air from their ordinary course into the heating
chamber K, but also, by raising or depressing one or more of them, to
regulate the degree of heat to be admitted to the steam tubes G. By these
means the temperature of the steam in the tubes is regulated at will. It may
be seen that the regulator valves M enable me to dispense with the use of
any steam valves whatever connected with the superheating apparatus ; direct
and continuous communication, therefore, is maintained between the boiler

page_text: and the cylinder of the engine without the addition of a single steam valve to
those commonly used in every steam engine. These regulator valves are,
moreover, indispensably necessary to my system of superheating steam, in
order to prevent the admission of an injurious degree of heat to the steam
tubes. That these regulator valves, therefore, may be worked with accuracy,
I make use of a steam guage or indicator, which is placed in any convenient
and prominent position. I do not restrict myself to any number of regulator
valves. There may be one or more, according to the form of the boiler, or to
suit any peculiarities of position or space. In the present instance I have
shown four valves; their disposition will depend upon the form of the boiler
employed, and the situation of the heating apparatus.
By cutting off the communication of the steam from the boiler with the
pipe F, and opening all the regulator valves M, and closing the passage
between the heating chamber K, which in the example I have given will
be at N, and the flues of the boiler, the heating apparatus may be entirely
isolated, and the steam will then take its usual course from the boiler to the
cylinder. The steam tubing may be composed of any material found con-
venient, but I consider cast iron best adapted for the purpose. Considering
the great degree of heat to which the tubes G must usually be subjected, and
the very rarefied state of the steam within them, it is especially necessary that
the junctions of these tubes, whether effected by means of flanges or otherwise,
should be accurately adjusted and impervious. To effect this object I surround
the joints of the tubes with a mastic, composed of clay, iron filings, ammonia,
or cloride of ammonium, or any other suitable matter.
As my apparatus may be applied to steam engines in present use, as well as
to those which may be erected hereafter, it must be evident that any particular
position for the parts of my apparatus with regard to the boiler and engine is
not absolutely essential for the affective operation of my Invention. I do not
therefore confine myself to any special arrangement of the various parts of the
apparatus.
I may observe that for stationary engines I consider the position of the
various parts of my apparatus as shown on the accompanying Drawings, to be
the most effective.
Having described my Invention, and the manner in which it may be carried
into effect, I conclude, by observing, that without restricting myself, as aforesaid,
to any precise details or arrangements, I consider as novel and original, and
therefore claim, the regulator valves, by the use of which the degree of heat
acting upon the steam tubes in the heating chamber may be regulated, thereby
modifying at will the intensity of the steam itself, which should never exceed

page_text: a certain temperature; and, finally, by the opening of which, combined with
other means, as herein-before stated, the action of the superheating apparatus
may be entirely suspended, thus leaving the steam to pursue its ordinary course
between the boiler and the engine.
In witness whereof, I, the said John Darlington, have hereunto set my
hand and seal, this Fifth day of February, in the year of our Lord
One thousand eight hundred and fifty-seven.
JOHN DARLINGTON. (L.s.)