IMPROVEMENTS IN APPARATUS FOR UTILISING THE EXHAUST STEAM OF STEAM ENGINES
Year: 1883

page_text: LETTERS PATENT to Herbert John Haddan, of Kensington, Middlesex, for an
Invention of IMPROVEMENTS IN APPARATUS FOR UTILISING THE EXHAUST
STEAM OF STEAM ENGINES communicated to him from abroad by Abraham
Zalm, of Rotterdam, Holland,
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at the
Office of the Commissioners of Patents on the 3rd March 1883.
IN
HERBERT JOHN HADDAN, of Kensington, Middlesex, "IMPROVEMENTS
APPARATUS FOR UTILIZING THE EXHAUST STEAM OF STEAM ENGINES," a com-
munication to me from abroad by Abraham Zalm, of Rotterdam, Holland
This invention has for its object to utilize exhaust steem by introducing it again
into the steam engine or boiler.
If the apparatus is applied to a steam-cylinder the exhaust steam is conducted
through a tube into one end of a second tube open at the other end and surrounded
by the tube which supplies live steam to the engine.
The inner tube is open towards the valve chest of the cylinder and com-
municates at the other end with the outer or supply tube by a valve adapted to be
automatically closed by the live steam.
At the same end the inner tube communicates also with the exhaust pipe by a
short pipe provided with a valve.
The inner pipe may contain a piston the rod of which passes through a stuffing
box and is connected with a counterweight.
The live steam flows through the annular space between the inner and outer
pipe, and in passing the lower edge of the inner pipe produces a suction in the
latter.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Herbert John Haddan in the Great Seal Patent Office on the
3rd September 1883.
HERBERT JOHN HADDAN, of Kensington, Middlesex,
"IMPROVEMENTS IN
APPARATUS FOR UTILIZING THE EXHAUST STEAM OF STEAM ENGINES," a com-
munication to me from abroad by Abraham Zalm, of Rotterdam, Holland,
In describing this invention reference will be had to the accompanying drawing
Fig. 1 and 2, in which x represents the cylinder of an ordinary steam engine
provided with a piston.
The introduction of the live steam as well as the discharge of the exhaust steam
takes place in the ordinary way, viz by means of a slide valve.
y represents part of the steam conducting tube or a tube in communication with
the same.
The tube y encloses the cylinder A the communication of which with
the tube y at C¹ may be interrupted by means of the valve D. This valve is
arranged in such a manner as to be automatically closed by the live steam leaving
the boiler. In Fig 2 this valve is shown in section. The cylinder A contains a
piston B with rod B¹ passing through the cover E of a stuffing box. The rod B¹
which is connected with a counterweight is of sufficient length to permit the piston
to descend to the bottom of the tube A.
The tube G which communicates with the interior of the slide valve, is connected
with the cylinder A through an opening capable of being closed by means of a
valve F.
When the slide valve occupies the position shown in the drawing, the two steam
ports of the cylinder x are closed, and the piston B occupies the position indicated
in the drawing.
.
If the piston B is caused to descend by means of the counterweight attached to
the rod B', the valve F¹ closes, while the valve D may remain at rest because the
pressure may be the same on both sides of the valve D. At this moment the
steam cylinder will be full of steam, the steam piston will occupy the position
indicated in the drawing and the two sides of the piston are exposed to steam of
low density.
When the steam piston is forced towards the other end of the cylinder x, the
steam enters the steam cylinder, and a current established in the conducting pipe,
which causes a diminution of the pressure below the piston B at C. The interior
of the slide valve is during this time in communication with tube G which receives
the steam from the back of the steam piston; this steam opens the valve F, follows
the piston B and enters the tube A. When the piston B is set in motion the
valve D closes owing to the pressure of the steam arriving from the boiler. The
steam ceases to flow as soon as the piston arrives at the end of its travel, because
the steam port of the cylinder is at this moment closed by the slide valve, the
valve F closes at the same time owing to the equalisation of pressure below the
piston B and on the valve D, and the piston B then slides back into its original
position forcing the exhaust steam from the tube A through D into the steam
conduit pipe.
Instead of leading the steam into the steam cylinder, it may be allowed to escape
into the air or conducted into a reservoir for condensation.
From the above it will be seen that it is only possible to reintroduce steam of
low pressure into the boiler, if there exists temporarily or permanently a vacuum
chamber or at least a pressure inferior to that of the steam to be reintroduced.
It will be easily understood that by the omission of the piston B and its
accessory, the valve D, and by closing this inlet, the exhaust steain may be

page_text: reintroduced into the boiler in the most simple manner, because the pressure
obtained in the tube A is diminished from time to time owing to the steam current
around and below the tube A.
In engines with two or more steam cylinders, a steam current may be con-
tinuously maintained in the steam conduit or in y, and in this manner the exhaust
steam continuously educted through A; consequently the valve D may be omitted
as well as the valve F which would then be replaced by a valve intercepting the
communication of the live steam with the interior of the slide valve when the
engine is to be stopped.
For the purpose of reintroducing the exhaust steam in a most simple manner
into the boiler, it is only required to conduct the same first into a space in which
exists a lower pressure owing to the steam current, to mix with the live steam
when leaving this space. In this case the cylinder A in the tube y is supposed to
be without the piston B and the valve D.
The cylinder y may be situated in the interior of the boiler.
It will be understood that the shape of the different parts and the construction
of the apparatus may vary as well as the material employed for the same.
Furthermore the steam may be reintroduced into the boiler directly or indirectly
by means of a steam conduit, or by a tube communicating with the same, or by
means of a reservoir for superheated steam, without departing from the principle of
this invention.
In witness whereof I the said Herbert John Haddan
have hereunto set my hand and seal this 29th day of H. J. HADDAN (L.S.)