AN IMPROVEMENT IN APPLYING STEAM OR OTHER AFRIFORM FLUIDS EXPANSIVELY IN ENGINES
Year: 1857

page_text: LETTERS PATENT to John Smith, of 4, Albion Square, South Side,
Dalston, in the County of Middlesex, for the Invention of "AN IMPROVEMENT
IN APPLYING STEAM OR OTHER AFRIFORM FLUIDS EXPANSIVELY IN ENGINES."
Sealed the 18th September 1857, and dated the 23rd March 1857.
PROVISIONAL SPECIFICATION left by the said John Smith at the
Office of the Commissioners of Patents, with his Petition, on the
23rd March 1857.
I, JOHN SMITH, of 4, Albion Square, South Side, Dalston, in the County of
Middlesex, do hereby declare the nature of the Invention for "AN IMPROVE-
MENT IN APPLYING STEAM OR OTHER AERIFORM FLUIDS EXPANSIVELY IN ENGINES,"
to be as follows:-
This Invention has for its object an improvement in applying steam or
other aeriform fluids expansively in engines. For this purpose what is called
a receiver or expansion chamber, by preference of larger capacity than the
engine with which it is used, is introduced between each two engines employed;
and such receiver or expansion chamber is so connected with the two engines
between which it is interposed, and the steam or aeriform fluid therein acts
on the opposite side of the piston of the first engine to that at which the
aeriform fluid enters from the boiler or generator; and such receiver or inter-
posed chamber is also connected with a second engine of larger capacity than
the first. The steam or acriform fluid from the first engine, after acting

page_text: on the piston therein, passes into the expansion chamber, and a fresh
quantity of steam or fluid is admitted from the generator. Another or
second receiver or expansion chamber is similarly interposed between the
second engine and a third engine of still larger capacity, and the steam or
fluid from the second engine, after actuating the piston therein, passes into
the second expansion chamber or receiver, and so on, whatever be the number
of engines employed in a series.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Smith in the Great Seal Patent Office on the
22nd September 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
SMITH, of 4, Albion Square, South Side, Dalston, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of March, 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 John Smith, Her special licence that I, the said John Smith, my
executors, administrators, and assigns, or such others as I, the said John
Smith, 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 "AN IMPROVEMENT IN
APPLYING STEAM OR OTHER AERIFORM FLUIDS EXPANSIVELY IN ENGINES" upon
the condition (amongst others) that I, the said John Smith, my executors
or administrators, 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 per-
formed, 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 Smith, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-

page_text: My Invention consists in the use of an expansion chamber or vessel in con-
junction with every two cylinders in a series of cylinders, so that the steam in
passing from any one cylinder to another shall pass through and become
accumulated to a certain extent in. the expansion chamber or vessel.
The means I prefer for practically carrying out this principle is sliewn in
the annexed Drawing, where C and C¹ represent a pair of: cylinders with the
usual appendages of valves, pistons,. &c., and R and R¹ two- expansion
chambers or vessels with appendages, to be afterwards described.
The first cylinder C is represented as receiving steam from an ordinary.
boiler (which is not shewn in the Drawing) through the pipe A. Instead of
exhausting into-the atmosphere or into a condenser, I permit the steam to flow
into the receiver R through the pipe B. This first receiver, as well as the
second receiver marked R', is represented as being partially filled with water,
and as being placed in contact with the heated air passing from the boiler
through the flue D. The steam from the first receiver C is represented as
being conducted through the pipe E to the second cylinder, which is of larger
capacity than the first cylinder. The exhaust steam from the second cylinder
proceeds to the second receiver through the pipe F, and this second receiver
may supply steam to a third cylinder, and so on, whatever be the number of
cylinders and receivers contained in a series, until the steam be finally ex-
hausted into the atmosphere or into a condenser.
In order to effect the proper working of my Invention, I prefer that the
cubical capacity of the cylinders should be such that the second shall be
double that of the first, and the third double that of the second, and so on.
Great care must be taken that the different parts of this engine be properly
proportioned, as they are all required to work simultaneously and har-
moniously; for instance, if we suppose that the pressure of steam on the piston
of the first cylinder be 64 lbs. gross pressure on the square inch or 49 lbs.
above the atmosphere, the pressure on the first receiver R will be about 32 lbs.
gross pressure, or 17 lbs. above the atmosphere; for, as the cubical capacity
of the second cylinder is double that of the first, there will be taken away at
every stroke of the second cylinder the same weight of steam as was required
for the first cylinder, but having its volume doubled; consequently, the area of
the steam and exhaust ports must be properly proportioned to meet this
increase of volume. Again, if the area of the piston of the first cylinder be
100 inches and the area of the pistons of the three succeeding cylinders be
200, 400, and 800 inches respectively, and if the pressure in the boiler be
64 lbs. gross pressure on the square inch, the back or exhaust pressure of
steam in the first receiver is 32 lbs. gross pressure on the square inch,

page_text: leaving an actual pressure of 32 lbs. per inch, or 3,200 lbs. throughout
the whole stroke. The gross pressure on the steam side of the piston of
the second cylinder is 32 lbs. per square inch, but as there is 16 lbs. per
square inch of a back or exhaust pressure, the actual available pressure on the
steam side of the piston is 16 lbs. per square inch; or multiplying this by 200
inches the area of the piston gives an actual available pressure on the piston
of 3,200 lbs. In the same way it will be found that there is a pressure also of
3,200 lbs. on the third piston, while on the fourth piston with the pressure in
the third receiver at 8 lbs. or 7 lbs. below the atmosphere, the total pres-
sure will be 6,400 lbs., exclusive of the resistance of the condenser, so that the
total actual available pressure on the four pistons would be 16,000 lbs; this
would be about the real pressure if there were no condensation of the steam
in its progress from the boiler to the condenser, if there were no vacuum
resistance, and if it were true that the volume of steam is precisely inversely
as its pressure. But taking these things into account, the total actual pressure
would be about 13,500 lbs., being a pressure three times greater than the pres-
sure on the piston of the first cylinder if it exhausted into the atmosphere,
and worked as an ordinary high-pressure engine.
The crank shaft of an engine constructed according to this Invention must
be such as to bear the strain from the four pistons; while the strength of the
piston rod and other attachments should be carefully calculated.
The Drawing represents an arrangement somewhat similar to the ordinary
horizontal engine, but with two cylinders placed in a line one behind the other:
Should more cylinders be requisite in a series, they may be arranged either in
pairs, each pair being connected with a crank on the crank shaft; or they may
all be placed with their centres in one line, the same piston rod being con-
tinued through all the cylinders, and connected with a crank in the usual
way; or, the cylinders may be arranged in any other way that may be deemed
advisable. I would recommend an engine having four cylinders, each pair
being connected with a crank on the crank shaft. I prefer the engine to be
so proportioned that the working pressure in the last cylinder should be about
5 lbs. below the pressure of the atmosphere, and that this cylinder should be
connected with a condenser. The slide valves may be connected as shewn in
the Drawing, and worked from one eccentric. Provision may be made to cut
off the steam at any given part of the stroke, in the same manner as it is
usually accomplished in steam engines.
The receivers I prefer to be of such a size, that each one shall have a steam
space from 5 to 10 times greater than the cubical capacity of the cylinder
which it supplies with steam. To prevent coudensation, I would recommend

page_text: that the receivers be placed so that they may receive heat from the heated
air passing from the boiler, and that the receivers as well as the cylinders and
steam pipes should be carefully clothed with non-conducting substances.
I would also recommend that the receivers be partially filled with water.
The receivers should be fitted with valves and pipes to allow the steam when
it has reached a certain point to escape from the one to the other, as is repre-
sented by the internal valve H, and the branch from the pipe E. The internal
valve H is weighted, so that when the steam in the first receiver rises beyond
a certain point, the valve will permit its escape into the second receiver. The
last receiver should be furnished with an escape valve to blow off into the
atmosphere when necessary. It may be advisable to connect the receivers
with the feed pipe that supplies the boiler with water, and to affix guage
cocks or water guages. The steam pipes leading to the cylinders are provided
with the usual valves or stop cocks for the admission of steam to the cylinders,
and ought to be fitted with suitable hand gear by which the valves may be
opened or shut simultaneously.
I. To prevent any one cylinder being subjected to great extremes of tempe-
rature, and so to prevent or lessen condensation some engines are supplied with
steam of 45 lbs. above the atmosphere; this steam has a temperature of
about 294° F, and expands down to 12 lbs. below the atmosphere when it
has a temperature of 141° F. It is obvious that the iron of that part of the
cylinder which came in contact with steam at 294° must be coming in contact
during the whole stroke with steam, whose temperature is continually diminish-
ing and finally reaches 141° F. On the return stroke (if the engine be
double-acting) that part of the iron which was formerly in contact with steam
at 94° F comes a second time into contact with steam at 141° Fahrenheit.
The iron must be cooled to such an extent, probably 150° Fahrenheit, that
condensation must naturally ensue when the steam at 294° comes in contact
with the cooled iron. By the use of a receiver in the manner or manners
described in this Invention, condensation is obviated to a great degree, and
hence there will be a gain of mechanical effect. If there were no receiver,
and if the steam from one cylinder proceeded direct to the next cylinder, the
range of temperature to which the first cylinder would be subjected would be
nearly double of what it would be if exhausted into a receiver.
II. The second advantage obtained by the use of the receiver is, that the
heat from the flues may, either wholly or partially, keep up the volume of

page_text: steam to its theoretic volume, either by evaporation from the water contained.
in the receivers, or by surcharging the steam contained in them.
III. The third advantage is, that great equality of motion is obtained,.and.
that steam can be expanded to a great extent without any necessity for
the expensive and cumberous machinery usually employed; for the steam will.
flow from any receiver into the cylinder with which it is connected, and.
produce nearly the same equable result as if it were flowing direct from the
boiler.
Having thus described the nature of my said Invention, and: the manner of
performing the same, I would have it understood that what I claim is the
application of expausion vessels or chambers, which I have called receivers, in
combination with the working cylinders of engines, when working steam or.
other æriform fluids expansively, as herein described,
In witness whereof, I, the said John Smith, have hereunto set my hand
and seal, this Nineteenth day of September, in the year of our Lord
One thousand eight hundred and fifty-seven.
Witness,
GEORGE HENRY SLIGHT,
Engineer,
Edinburgh.
JOHN SMITH. (L.S.)