Improvements in and Apparatus for Superheating Steam and Applying the same to Steam Engines.
Year: 1889

page_text: Date of Application, 19th Mar., 1889
Complete Specification Left, 19th Dec., 1889-Accepted, 25th Jan., 1890
PROVISIONAL SPECIFICATION.
Improvements in and Apparatus for Superheating Steam and
Applying the same to Steam Engines.
I GEORG SCHIMMING manufacturer of Berlin in the Kingdom of Prussia and
German Empire do hereby declare the naturo of this invention to be as follows :—
The object of this invention is to overcome the difficulties hitherto experienced
in the employment of superheated steam in steam engines owing to the rapid
destruction of the valve faces steam pipes packings and non conducting materials used
for clothing the pipes.
This object I attain by superheating the steam in the cylinder itself by mixing
therewith an exploded mixture of hydrocarbon and nir.
According to this invention to the ends of the steam cylinder I attach a cylinder
or cylinders wherein a mixture of gas or other hydrocarbon and air may be exploded
the aforesaid cylinder or cylinders are fitted with pistons attached by a rod to a dash-
pot or piston working in a cylinder to which boiler steam is admitted at the back of
the piston to form a cushion or buffer.
A mixture of air and hydrocarbon is admitted to the explosion cylinders by means
of suitable valves and ignited by means of a lighted jet and firing slide as in gas
engines.
At the period of cut off in the main cylinder just after igniting the explosive
mixture communication is opened between the main steam and explosion cylinders
by means of a suitable valve the heated hydrocarbons rush into the steam cylinder
and superheat the steam therein and the mixture of steam and hydrocarbon acts on
the main piston to the end of the stroke thereof. When the motion of the main
piston is reversed the communication between the main cylinder and explosion
cylinder or cylinders is closed the steam and gases in the said cylinders are passed to
the condenser or in the case of compound engines the exhaust from the main cylinder
passed to the next cylinder and ultimately to the condenser.
The mixture of hydrocarbon and air is compressed before ignition as in gas
engines and the quantity thereof is so regulated that the steam in the main cylinder
is heated to about 300° to 400° temperature.
The valve between the main and explosion cylinders may be actuated from the
explosion piston by means of suitable linkwork.
The steam cushion is effected as follows the port admitting boiler steam opens into
the supplementary steam cylinder at a distance from the closed end thereof and the
piston working in the said cylinder on being forced inwards passes over the port
and compresses the steam between it and the end of the cylinder sufficiently to
arrest its motion. Instead of this an hydraulic buffer or dash-pot may be used the
piston forcing the liquid out of the cylinder through a small aperture.
Dated this 19th day of March 1889.
BROWNE & Co.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in and Apparatus for Superheating Steam and
Applying the same to Steam Engines.
[ GEORG SCHIMMING manufacturer, of Berlin in the Kingdom of Prussia and
German Empire do hereby declare the nature of this invention and in what manner
the same is to be performed, to he particularly described and ascertained in and
by the following statement :-
The object of this invention is to overcome the difficulties hitherto experienced in
the employment of superheated steam in stenin engines owing to the rapid destruction
of the valve faces steam pipes packings and non conducting materials used for
clothing the pipes. This object I attain by superheating the steam in the cylinder itself
by mixing therewfth an exploded mixture of bydrocarbon and air.
According to this invention to the ends of the steam cylinder I attach a cylinder
or cylinders wherein a mixture of gas or other hydrocarbon and air may bo
exploded the aforesaid cylinder or cylinders are fitted with pistons attached by a
rod to a dash-pot or piston working in a cylinder to which boiler steam is admitted
at the back of the piston to form a cushion or buffer.
The practical application of my method in superheating steam by mixing an
exploded mixture of hydrocarbon and air therewith is exemplified in the accom-
panying sheet of drawings which shews apparatus constructed according to this
invention applied to a compound tandem steain engine.
Figure 1 is a horizontal longitudinal section through the apparatus.
Figures 2 and 3 are horizontal longitudinal sections through one explosion cylinder
of the apparatus.
Figure 4. is cross section through the high-pressure steam cylinder and an explosion
cylinder and valve chest.
Figure 5. are indicator diagrams from the engine shewn in Figure 1 when working
as an ordinary compound and when working with steam superheated according to
this invention.
The engine shewn in Figure 1 is similar in general construction to an ordinary
tandem compound steam engine.
A is the high pressure cylinder in which works the piston D, B. the low pressure
cylinder, (1. the air pump. The steam from the boiler passes into the high pressure
cylinder by the double scat valves a. and b. which are provided above the cylinder
and indicated by dotted lines in Figure 1. These inlet valves are operated by the
excentrics c. and d. Below the cylinder and vertically under the inlet valves are
provided exhaust valves controlled by the excentrics c. and f. The steam exhausted
from the high pressure cylinder by these valves passes into the low pressure
cylinder B. and thence to the condenser.
Upon the high pressure cylinder A. are provided the explosion cylinders E. and J.
in which work pistons G. separated from the steam cylinder A by piston valves F.
So soon as the piston D. cominences its stroke towards the left the inlet valve a. opens
and as soon as the piston D has completed one fifth of its stroke valve a. closes at this
moment an electric spark ignites the mixture of inflammable gas and air contained
in the explosion cylinder E. and the passages. The mixture of gas and air in E.
explodes and by the high pressure of the exploding gases the piston valvo F. (to the
opposite-face whereof steam under boiler pressure is admitted) is thrown back (see
Figure II.) and the highly heated gases pass from the explosion cylinder through
port M. into the steam space of the high pressure cylinder A. The passage of highly
heated gases from explosion cylinder E. to the steam cylinder A. takes place
throughout the remainder of the movement of piston D. to the left and during a
portion of the stroke towards the right, by reason of the retreating motion of
piston G.
The work obtainable when the engine shown in Figure 1 is worked as a simple
steam engine, not actuated by superheated steam, is in Figure 5 shown by the

page_text: surface 012560. By superheating the pressure is raised from 2 to 3 and the work is
increased by the surface 23452-5706. The extent of this effect is determined by the
degree of superheating.
The explosion chamber is filled with a mixture of air and gas in the following
manner. The gas compressor G₁ owing to the motion of piston H. draws gas and
air mixed in proper proportions through the slide h. As soon as the return stroke of
the piston H. begins, the slide h. opens the outlet for leading away the compressed
mixture of gas and air as shown on slide i. The pipe for conducting away the com-
pressed mixture of gas and air leads to the inlet ports of the explosion cylinder. In
Figure 1 the slide k. opens the gas inlet for the explosion cylinder J. by the return of
the piston in the explosion cylinder and the forward motion of the piston in the air
and gas compressor the mixture of gas and air is passed into the explosion cylinder
as however the explosion cylinder has only half the capacity of the air and gas com-
pressor the mixture of air and gas is at the end of the stroke (as shewn in the
explosion chamber E Figure 1, and after the slide l. is closed) compressed to about
30 pound per square inch. The space at the right hand side of the piston G. com-
municates with with the steam pipe carrying steam from the boiler to the engine.
When the piston G. moves the steam cools the walls of the explosion cylinder. The
piston valve F. is acted upon by steam at boiler pressure as is the cylinder K. in
which the same works by a port m. connected with the slide box L. and the latter
also communicates with the pipe which supplies steam from the boiler to the engine.
The port m. is connected with port y. by a slide n. The slide n. is operated from the
piston rod of piston G. by the lever . pivoted at v. and by the rod y. on the piston
valve F.
As soon as the explosion cylinder E. is filled with the mixture of gas and air, soe
Figure 1, this is exploded by the electric spark or other suitable means at g. By the
explosion the piston valve F. is thrown back as shewn in Figure II. and thus the
slide n. brought into the position shown so that the spaces at either side of the piston
communicate with one another. To prevent the slide n. being lifted off its face by
the explosion it has broad lugs at the sides as shown in Figure IV. covering channols
communicating with the atmosphere. At the moment of the explosion the piston
valve is thrown back over the port m. and stopped by the pressure of the steam
behind it.
Immediately after this the piston valve recedes to the position shewn in Figure III.
being actuated by the compressed cut off steam and the steam passing through a small
port p. from the slide box. At the moment of the explosion the steam contained in
the space to the left of the piston valve passes through the ports 7. and r. to E. is
thero superheated whilst it cools the explosion chamber. This volume of steam thus
superheated will vary in amount in machines of different construction. By the same
path and throughout the time during which the slide n. is in approximately the
position shewn in Figure 11I. and whilst the piston valve is open, fresh steam to cool
the parts enters by the narrow port p. and through the ports q. and r. into the
explosion cylinder E. and by port M into the cylinder A.
As soon as the piston G. in the explosion cylinder E. on its return stroke arrives
into the position shown in Figure III. the slide n. opens the port m. fresh steam passes
behind the piston valve F. closing the same.
To prevent shock when the valve closes the oil pump N is connected with the
piston rod y. of the piston valve F. Shortly after the piston valve has closed the
port M, the outlet valve S. opens until piston G has completed its return stroke, when
it will close. The valve S. is controlled by an excentric Z.
It will be obvious that my invention is without departure from its governing
principle or substantial change of structural elements equally applicable to single
triple and quadruple expansion steam engines as to the compound engine selected for
illustration.
It is moreover clear that in place of the steam compressed air may be admitted
into the cylinder A Figure I. and the same operations above described may take place,

page_text: then the machine works with compressed superheated air the air pump being dispensed
with.
It is also clear that as in gas motors in lieu of gas finely atomised combustible
liquids mixed with air may be exploded and employed for superheating steam and air
in a machine constructed in accordance with my invention and that receivers of
different form may take the place of the explosion cylinder.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is :-
I. The method of superheating the steam for operating prime movers, by the intro-
duction of inflammable gases or other inflammable substances suitably mixed with air
into explosion chambers, igniting such mixture in said explosion chambers and
mingling the products of the explosion of said mixture with the steam serving to
operate such prime movers substantially as set forth.
11. In an apparatus for superheating steam and applying the same to steam
engines. The automatic valve for opening and closing the communication between
steam and explosion cylinders substantially as described.
III. The improved apparatus for superheating steam and applying the same to
steam engines substantially as described and shown.
Dated this 18th day of December 1889.
BROWNE & Co.,
Agents for Applicant.