IMPROVEMENTS IN STEAM EXGINDS
Year: 1860

page_text: LETTERS PATENT to Francis Herbert Wenham, of Brixton, in the County
of Surrey, Engineer, for the Invention of "IMPROVEMENTS IN STEAM
EXGINDS"
Sealed the 4th December 1860, and dated the 6th June 1860.
PROVISIONAL SPECIFICATION left by the said Francis Herbert Wenham
at the Office of the Commissioners of Patents, with his Petition, on the
6th June 1860.
I, FRANOIS HERBERT WENHAM, of Brixton, in the County of Surrey,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN STEAM ENGINES," to be as follows:-
This Invention is applicable to steam engines worked on the high-pressure
condensing principle in the following manner :-Steam of a high pressure is
led direct from the boiler to a cylinder of comparative small size, after
having been there worked expansively, it is returned into a series of pipes
placed in the smoke box known as a "superheater;" being thus surcharged
with beat it is next conveyed into a second cylinder of larger size. After
being again worked expansively it is superheated a second time by a separate
heater, and passed into a third cylinder of still larger size, and after being
therein expanded to its fullest extent it is finally exhausted into the condenser.
IP 8d1

page_text: The pistons of the three cylinders may all work on the same shaft by cranks at
equi-distant radii. The superheated steam in its transit to one cylinder may
be conveyed through a case containing a series of pipes in which the steam
will be heated in its passage to the following cylinder. The induction steam
of the preceding cylinder thus giving up a portion of its surplus heat for the
use of the steam going on to the next cylinder.
A second part of my improvements relate to heating steam during its
expansion in one or more cylinders. A small quantity of very hot steam
obtained from the boiler by passing it through a coil of pipes fixed either in
the chimney or flues, or in proximity with the furnace, is conveyed into the
cylinder during expansion, or after the main working supply of steam has
been cut off; this may be effected either by a separate pipe leading to the
top and bottom of the cylinder, the alternate action being obtained by a
four-way cock or system of valves. Or the hot steanı may be conveyed into
the space between the expansion valve and the slide, or steam valve of the
engine, so that after the expansion valve is closed and the working supply of
steam cut off a jet of hot steam may continue to flow into the cylinder during
expansion to the end of the stroke.
Having thus described the nature and action of my Invention. I would
have it understood that I claim the intermediate application of superheating
steam in its progressive expansion between two or three cylinders, that is to
say, in its passage between the first and second, and from the second to
the third.
I also claim the mode of superheating next described, or the superheated
steam before entering one cylinder being made to give up a portion of its
surplus heat for heating the steam passing on to the next by means of a
system of pipes placed vertically or horizontally.
And I further claim the mode of conveying a portion of very hot steam
into the cylinder during expansion after the main supply has been cut off
applied to expansive engines in the manner I have described.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Francis Herbert Wenham in the Great Seal Patent Office on
the 4th December 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
HERBERT WENHAM, of Brixton, in the County of Surrey, Engineer, send
greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of June, in the year of our Lord One
thousand eight hundred and sixty, in the twenty-third year of Her reign, did;
for Herself, Her heirs and successors, give and grant unto me, the said
Francis Herbert Wenham, Her special licence that I, the said Francis Herbert
Wenham,myexecutors,administrators, and assigns, or such others as I, thesaid
Francis Herbert Wenham, 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 STEAM ENGINES," upon the condition (amongst others)
that I, the said Francis Herbert Wenham, my executors or adminis-
trators, by an instrument 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 immediately after the date of the said Letters
Patent.
NOW KNOW YE, that 1, the said Francis Herbert Wenham, 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 and accompanying Drawings (that is to say) :-
This Invention is applicable to steam engines, worked either on the high
pressure alone, or combined with the condensing principle, in the following
manner-Steam of a high pressure is led direct from the boiler to a cylinder
of comparative small size. After having been there worked expansively, it is
returned into a series of pipes placed in the smoke box, kuown as a "super-
heater "being thus surcharged with heat; it is next conveyed into a second
cylinder of larger size. After being again worked expansively it is superheated
a second time by a separate heater, and passed into a third cylinder of still
larger size, and after being therein expanded to its fullest extent, it is finally
discharged or exhausted into the condenser. The pistons of the three cylinders
may all work the same shaft by cranks at equidistant radii. The superheated
steam in its passage to one cylinder may be conveyed through a case containing
a series of pipes, by which means the steam will be heated in its transit to the
following cylinder, the induction steam of the preceeding thus giving up a
portion of its surplus heat for the use of the steam going on to the next
cylinder, as shown in the Drawing, Fig. 1. Steam of a high pressure is

page_text: conveyed to work the small cylinder No. 1 through the induction pipe a; it is
then returned by the eduction pipe 6 to a superheater, placed in the smoke
box; after being therein surcharged with heat it is passed by the pipe c through
a series of tubes contained in the case d to cylinder No. 2. The steam after
having therein worked expansively is led by the eduction passage e into the
superheating case d, wherein it acquires heat from the surcharged induction
steam, and is again worked expansively in cylinder No. 3; from thence it is
finally exhausted or led to the condenser by the eduction pipe f.
Fig.2 shows the application of these principles to locomotive or agricultural
engines, being a transverse section taken through the steam cylinders, smoke
box, and superheater, which is represented as a short cylinder containing tubes
coincident with those in the boiler. Steam is first led from the boiler a
to the small cylinder 6; after having worked therein it is conveyed by the
eduction pipe c into the superheater d; after being thereinheatedit is conveyed
by a pipe e from the opposite side, into a second cylinder foflarger size; and
having therein worked it is discharged into the chimney or atmosphere by the
jet g as usual.
A second part of my improvements relate to heating steam during its
expansion in one or more cylinders; a small quantity of very hot steam
obtained from the boiler by passing it through a coil of pipes fixed either in
the chimney flues or in proximity with the furnace is conveyed into the
cylinder during expansion, or after the main working supply of steam has
been cut off; this may either be effected by a separate pipe leading to the
top and bottom of the cylinder, the alternate action being obtained by a
four-way cock, or system of valves, or the hot steam may be conveyed into
the space between the expansion valve, and the slide or steam valve of the
engine, so that after the expansion valve is closed, and the working supply of
steam cut off, a jet of hot steam may continue to flow into the cylinder during
the expansion to the end of the stroke.
Having thus described the nature and action of my Invention, I would
have it understood, that I claim the intermediate application of superheating
steam in its progressive expansion between two or three cylinders, that is to
say, in its passage between the first and second, and also from the second to
the third.
I also claim the mode of superheating as described in the Drawing. The
superheated steam before entering one cylinder being made to give up a
portion of its surplus heat for heating the steam passing to the next by means
of a system of pipes placed vertically or horizontally as shown.
And I further claim the mode of conveying a portion of very hot steam

page_text: nto the cylinder of an ordinary expansion engine, during the time the steam
s expanding, and after the main supply has been cut off, applied in the manner
I have described.
In witness whereof, I, the said Francis Herbert Wenham, have hereunto
set my hand and seal, this Twenty-ninth day of November, in the
year of our Lord One thousand eight hundred and sixty.
F. H. WENHAM. (L.S.)