Improved Steam Engine.
Year: 1895

page_text: Date of Application, 31st Aug., 1895-Accepted, 16th Nov.,
1895
Improved Steam Engine.
I, HENRY DAVEY, of 3 Princes Street, Westminster, in the County of
Middlesex, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
My invention consists of an improved form of steam engine, in which the cylinders
are single acting, with an arrangement by means of which the feed water is heated
on its way to the boiler, to a higher temperature than it would be heated by the
exhaust steam.
Fig. 1 is a sectional elevation of a compound pumping engine in accordance with
my invention.
There are two steam cylinders A. and B. with pistons C. and D. attached to a
rocking beam E., so that when the piston C. is moving upwards, the piston D. is
moving downwards.
The distribution of steam to and from the steam cylinders is effected as shown
on the drawing by means of double heat valves, actuated by means of the valve
gear described in my Patent No. 13,26987; or the steam distribution may be
effected by other means, such as slide or Corliss valves.
During the upward stroke of the piston C, steam from the boiler is being admitted
through the valve F, whilst steam from above the piston C, is passing to the top
of the piston D, and steam from below the piston D, is being discharged through
the feed heater G into the exhaust pipe H. During the down stroke of the
piston C, the steam admitted from the boiler during the previous upstroke is being
passed from below to above the piston C, and steam is also being passed at the
same time from above the piston D to below it.
In other words both pistons are in equilibrium and the downward motion of the
pump rod U. is effected by its own weight.
During the upstroke of the piston C. the steam valves F, and K. and the exhaust
valve M are open, whilst the two equilibrium valves J. and L. are closed. During
the return stroke the valves F and K and M. are closed, and the two equilibrium
valves J. and L are open.
G and N are feed water heaters; through the heater G. the exhaust steam from
the cylinder B is passed, when the valve M is open.
During the equilibrium stroke when the valve L. is open steam passes into the
heater N. through the non-return valve O.
The feed heaters are constructed with tubes, and the feed water is passed on its
way to the boiler through the pipe P. to the heater G., theuce through the pipe Q.
to the heater N. and thence through pipe R. to the boiler.
The feed water is thus heated, first in the heater G. by the exhaust steam, and
then to a higher temperature in heater N. by some of the steam from the equilibrium
stroke. To prevent the heater N. being choked up with water or air, a small pipe
connection S. is made to the exhaust pipe, provided with a regulating cock T.
The regulating cock can be adjusted to the required opening.
I make the engine when it is desired to do so with three or more cylinders, the
distribution of steam, and the application of the feed heaters remaining the same.
The distribution of steam in a three cylinder engine is indicated in Fig. 2.
Sheet 2. by the lines and arrows.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1st. An engine working on the Cornish cycle of steam distribution having the
feed water heater N. substantially as described and illustrated.
2nd. The combination of the feed water heaters G. and N. in the manner
substantially as described and illustrated.
Dated this 29th day of Avonet 1895
HENRY DAVEY.