IMPROVE MENTS IN APPARATUS FOR GENERATING AND SUPERHEATING STEAM
Year: 1857

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,.
in the County of Middlesex, and of 166, Buchanan Street, in the City
of Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE
Sealed the 15th September 1857, and dated the 14th April 1857.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on the
14th April 1857.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North Britain,
Gentleman, do hereby declare the nature of the said Invention for "IMPROVE
MENTS IN APPARATUS FOR GENERATING AND SUPERHEATING STEAM," a communication
from Auguste Prouvost, of Lille, in the Empire of France, Spinner, to be as
follows:-
This Invention relates to a peculiar construction and arrangement of
apparatus for generating and superheating steam, applicable also to the,
regenerating of steam after it has been used by the steam engine.
According to this Invention, the boiler or generator is placed at some distance
from the furnace, and is heated merely by the play of the flames round its

page_text: exterior sides, and through a central flue running longitudinally through the
boiler to the chimney.
The intermediate space or flue between the boiler and the furnace is filled
with pipes, which pass along it in two series in a zig-zag or serpentine direction,
both series or sets communicating at one end with a valve chest in connection
with the boiler, and at the other with a second valve chest communicating with
the pipe leading to the engine.
The pipes round the sides of the flue, and which are in contact therewith,
are of a square or rectangular section, so as to cover as much as possible the
brickwork, whilst the pipes which are in the central portion of the flue are of a
circular section.
The valves consist of slides, which work over the two mouths of the two sets
of superheating pipes, so that each set may be brought into action alternately,
the valves working in concert for that purpose.
As the steam is generated it passes along the heating pipes which are in the
hottest part of the flues, and becomes dried and surcharged before reaching the
engine; and, if found desirable, the steam after it has done its work in
the engine may be returned to the boiler again to be regenerated and heated,
the pressure in the boiler being sufficiently low to admit of this arrange-
ment.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 14th October 1857...
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of 166, Buchanan Street, in the City of Glasgow, North Britain, Gentle-
man, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of April, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Jolin
Henry Johnson, Her special license that I, the said John Henry Johnson; my
executors, administrators, and assigns, or such others as I, the said John Henry
Johnson, my executors, administrators, or 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,

page_text: and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
APPARATUS FOR GENERATING AND SUPERHEATING STEAM," a communication from
Auguste Prouvost, of Lille, in the Empire of France, Spinner, upon the
condition (amongst others) that I, the said John Henry Johnson, by an
instrument in writing under my hand and seal, 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 immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the samo is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :-
The said Invention relates to a peculiar construction and arrangement of
apparatus for generating and superheating steam, applicable also to the
regenerating of steam after it has been used by the steam engine.
According to one modification of this Invention, the boiler or generator
which is heated by the play of the flames round its exterior sides and through
a central flue running longitudinally through the boiler to the chimney. The
intermediate space or flue between the boiler and the furnace is filled with
pipes, which pass along it in two series in a zig-zag or serpentine direction
both series or sets communicating at one end with a valve chest in connection
5 with the boiler, and at the other with a second valvo chest communicating
with the pipe leading to the engine.
The pipes round the sides of the flue, and which are in contact therewith,
are of a square or rectangular section, so as to cover as much as posible the
brickwork, whilst the pipes which are in the central portion of the flue are of
O a circular section.
The valves consist of slides, which work over the two mouths of the two sets
of superheating pipes, so that each set may be brought into action alternately,
the valves working in concert for that purpose. As the steam is generated
it passes along the heating pipes which are in the hottest part of the flues,
5 and becomes dried and surcharged before reaching the engine; and, if found
desirable, this steam after it has done its work in the engine may be returned
to the boiler again to be re-generated and heated, the pressure in the boiler
being sufficiently low to admit of this mode of working.
According to another modification of this Invention, there: be substituted
may

page_text: for the zig-zag or surpentine tubes, previously mentioned, four tubes of larger
area, and having a circular section; two of these may be arranged at each
side of the boiler, with one end of each communicating with the boiler and the
other end with the steam cylinder, tho communication with the boiler and
the cylinder being alternately made and cut off in each pair by means of slide
valves.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed,
the same letters of reference indicating corresponding parts throughout all the
Figures.
Figure 1 on the Sheet of Drawings represents a longitudinal section of my
improved apparatus; Figure 2 is a vertical section through the line 1-2, in
Figure 4; Figure 3 is a transverse section through the line 3 and 4 in
Figure 4; Figure 4 is a general plan of the whole.
The steam produced in the generator A, (which may be an ordinary cylin-
drical boiler, as shewn, with or without flues, or a tubular boiler,) is taken along.
the short pipe a (which branches off in opposite directions) into the casings
C, C¹, which are fitted with slide valves D and D', whose function is to admit
the steam into the superheaters B and B alternately.
The motion of these slide valves is communicated by the excentrics or
cams and 6 by means of the levers f. When the slide valve D is open,
the steam after leaving the boiler passes along the corresponding super-
heating tube B and enters by the pipe c to the valve casing E. In its
passage along the entire length of the tube B the steam acquires a great
accession of heat, and by means of the steam case E and slide valve F
performs its office in the cylinder H in the ordinary way. The steam
which had effected the preceeding stroke of the piston is driven back into
the boiler through the pipe d. The tubes B and B¹ being only alternately
in communication with the boiler, the steam is retained sufficiently long
in them to acquire a greatly increased temperature and power, and for
this purpose the slide valves D and D' are fitted to the end of each super-
heating tube.
By this arrangement the steam does not gain access to the cylinder until
after it has been retained a short time in the superheating tubes. With a
.view of regulating this superheated steam, and also of adjusting it to the
amount of work to be performed by the engine, the pipe g communicating
with the superheating tube is furnished with an equilibrium safety valve,
which must be weighted to the desired amount. The steam that escapes

page_text: when the pressure overcomes the valve finds its way into the boiler by means
of the small pipo g.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe, in conclusion, that I do not confine or restrict myself to
the precise details or arrangements which I have had occasion to describe
or refer to, as variations may be made therefrom without deviating from the
principles or main features of the said Invention, nor do I claim any of the
mechanical elements of which the said apparatus and parts of apparatus are
respectively composed as being separately or apart from the use or application
of such elements to form the combinations constituting such apparatus and
parts of apparatus respectively as being any part of the said Invention; but
what I consider to be novel and original, and therefore claim as the
Invention secured to me by the herein-before in part recited Letters
Patent, is,―
First, the general arrangement and combination of apparatus for generating
and superheating steam, as herein-before described, and shewn in the
Drawings.
Second, the general construction and arrangement of boiler and its acces-
sories for the purpose of regenerating steam, as herein-before described, and
shewn in the Drawings.
Third, the system or mode of superheating steam after leaving the boiler, as
herein-before described, and shewn in the Drawings.
Fourth, the system or mode of placing the superheating tubes in com-
munication with the boiler in order to regulate differences in the tension of the
steam by means of an equilibrium safety valve, as herein-beforo described, and
shewn in the Drawings.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, this Fourteenth day of October, One thousand
eight hundred and fifty-seven.