CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1871

page_text: LETTERS PATENT to Ernst Körting, of Hanover, in the Empire of
Germany, Engineer, for the Invention of "CERTAIN IMPROVEMENTS IN
STEAM ENGINES."
Sealed the 22nd March 1872, and dated the 29th November 1871.
PROVISIONAL SPECIFICATION left by the said Ernst Körting at the
Office of the Commissioners of Patents, with his Petition, on the
29th November 1871.
I, ERNST KÖRTING, of Hanover, in the Empire of Germany, Engineer,
do hereby declare the nature of the said Invention for "CERTAIN IM-
PROVEMENTS IN STEAM ENGINES," to be as follows:-
This Invention essentially consists in a new method of gaining back
again under pressure part of the exhaust steam of steam engines without
increasing thereby the back pressure on the piston of the engine, by
dividing the exhaust steam at the moment of its leaving the exhaust
port of the cylinder in two parts, one with high pressure and one with
low pressure. This object is obtained by applying a special apparatus,
which I call a "pressure restorer," to the exhaust pipe of the cylinder,
as near to the exhaust port as possible.

page_text: The bore of the diverging tube will be generally as large or slightly
larger than the area of the mouth of the exhaust nozzle for the purpose
of gaining back under pressure as much steam as possible. In many
cases however it might also be of much less bore.
The overflow space and the pipe leading from it is in continual free
communication with either the open air or with the condenser, and its
area being as large or larger than the area of the mouth of the exhaust
nozzle, it is evident that the apparatus can never give occasion to an
increase of back pressure in the cylinder.
The working of the pressure restoring apparatus when fitted to an
engine is as follows:-The steam of the before-mentioned first period of
exhaust will rush with great velocity through the exhaust nozzle, and
passing the overflow space will enter the diverging tube, where it
converts the velocity partly into pressure, forcing open the back-pressure
valve and entering the space behind, generally formed as a store or air
vessel. The steam of the second period of exhaust will pass the exhaust
nozzle with much less velocity, and the corresponding pressure will not
be sufficient to overcome the pressure on the valve, therefore the steam
will all pass through the overflow space, and the pipe leading from it
will convey the steam to any convenient place. The same process will
be repeated with every stroke of the engine, and the evident result is an
almost perfect separation of the high-pressure steam from the low-
pressure steam remaining in the cylinder at the end of each stroke
without any damage to the effect of the engine. The diverging tube
might be replaced by a short straight tube in many cases, where the
object of the application of the apparatus chiefly is to discharge part of
the exhaust steam into the atmosphere, and to take only the rest to the
condenser for the purpose of saving condensing water. The steam
restored under pressure may be used for any useful purpose either for
heating or for developing power, or for increasing the original engine
power. The construction of the apparatus may be varied and modified.
The following are some of the useful purposes to which this apparatus
may be applied :-
1st. The steam restored under pressure may be used to work another
steam engine either connected or not with the original engine. The
advantage of this combination compared with other compound engines
s, that the back pressure from the low-pressure cylinder on the piston
of the high-pressure one is removed altogether, both engines acting as

page_text: condensing engines by taking the overflow steam from the first cylinder
and all the exhaust from the second cylinder to the condenser.
2nd. The pressure restoring apparatus may be applied to condensing
engines when water for condensing purposes is scarce, to discharge part
of the exhaust steam through the diverging tube into the open air or 5
into any
other space when necessary, and to take only the rest of the
exhaust through the overflow pipe to the condenser. The back-pressure
valve prevents any air from entering the condenser.
3rd. The steam restored under pressure may be very usefully applied
for increasing the draught in steam boilers by blowing it through a blast
pipe into the chimney of the boiler. The continuous blast will have a
much better effect upon the draught than the intermittent action of the
exhaust, being conveyed directly from the cylinder into the chimney as
usually done.
4th. The steam restored under pressure may very usefully work an
injector for feeding the boiler, thus combining in a most perfect manner
the boiler feeding apparatus with a feed water heating apparatus through
exhaust steam.
5th. The steam restored under pressure may very usefully be applied
to produce a partial vacuum behind the piston of the engine during the
second period of exhaust by working a blast vacuum apparatus, thus
exhausting through the action of a continuous jet the steam remaining
in the cylinder after the first period of exhaust.
6th. The steam restored under pressure may be used to produce a
vacuum or partial vacuum behind the piston of the engine during the
second period of exhaust by forming the driving medium of the cold
water jet in a jet condenser.
7th. The pressure restoring apparatus may be applied in combination
with a condenser of any system to discharge by direct action the con-
densing water in all cases when the final pressure at the end of the
stroke in the cylinder is higher than the pressure of the atmosphere.
The principle of the combination is that the lowest part of the condenser
being above the level of the chamber or space immediately over the
back-pressure valve of the pressure restoring apparatus is brought in
communication with their chamber through a pipe, in which pipe again
a valve is placed opening from condensers self-acting against the

page_text: pressure restoring apparatus. The steam of the first period of exhaust
will enter the diverging tube, force open the back-pressure valve, and
will discharge together with any liquid gathered behind the valve into
the open air. The valve in the communication pipe will be kept closed
all this time by the pressure in the diverging tube. With the com-
mencement of the second period of exhaust the steam will pass through
the overflow space into the condenser, the same vacuum will be esta-
blished in the cylinder in the pressure restoring apparatus and in the
condenser, the back-pressure valve will be kept shut by the pressure of
the atmosphere, and the valve in the communication pipe will be opened
by the liquid gathered in the meantime in the lower parts of the con-
denser, and this liquid will flow through the above pipe and enter the
chamber over the back-pressure valve to become discharged during the
first period of the following exhaust. This construction and arrange-
ment gives the advantages of saving the air pump, and of saving part
of the condensing water, and, finally, of heating the condensing water
again by the steam of the first period of exhaust, thus giving the
advantage of a perfect feed water heating apparatus also.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Ernst Körting in the Great Seal Patent Office
on the 29th May 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ERNST
KÖRTING, of Hanover, in the Empire of Germany, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of November, in the
year of our Lord. One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Ernst Körting, Her special licence
that I, the said Ernst Körting, my executors, administrators, and
assigns, or such others as I, the said Ernst Körting, 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 "CERTAIN IM-

page_text: PROVEMENTS IN STEAM ENGINES," upon the condition (amongst others) that
I, the said Ernst Körting, my executors or administrators, by an in-
strument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said In-
vention, 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 I, the said Ernst Körting, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Drawings and to the letters and figures marked thereon, that is to
say:
This Invention essentially consists in a new method of gaining back
again under pressure part of the exhaust steam of steam engines without
increasing thereby the back pressure on the piston of the engine, by
dividing the exhaust steam at the moment of its leaving the exhaust
port of the cylinder in two parts, one with high pressure and one with
low pressure. This object is obtained by the application of an apparatus,
which I call "pressure restorer," to the exhaust pipe of the cylinder, as
near to the exhaust port as possible.
The construction of this apparatus is based on the general principle
and construction of ordinary steam engines, and on the fact that the
steam like any other fluid or liquid will keep its straight direction as
much as possible when moving, and if introduced into a diverging
tube will convert its velocity into pressure according to the increasing
sectional area of the diverging tube. The process of the exhaust
steam leaving the cylinder may be considered as occurring in two
distinct periods or stages.
The first period or stage represents the sudden equalizing of the
pressure existing in the cylinder at the end of each stroke either with
the pressure of the atmosphere or with the pressure in the condenser at
the moment of the valve putting the steam port in communication with
the exhaust port.
The second period or stage represents the continual exhaust of the
steem then still in the cylinder and forced out by the hack movement of

page_text: The pressure restoring apparatus is intended to reutilize or again
make useful the steam leaving the cylinder according to its final pressure
with great velocity during the above first period, allowing however the
steam leaving the cylinder during the second period to take its way as
easily as possible either into the open air or into the condenser.
aranys improvemeNS IN DIEwm Lyones.
The pressure restoring apparatus is intended to reutilize or again
make useful the steam leaving the cylinder according to its final pressure
with great velocity during the above first period, allowing however the
steam leaving the cylinder during the second period to take its way as
easily as possible either into the open air or into the condenser.
In all cases where the exhaust port of the engine is opened suddenly,
and the discharge of exhaust takes place at once with full power the
apparatus must consist of four essential parts, viz. :—
a an exhaust nozzle to impart a certain direction to the exhaust steam.
6 a diverging tube or receiving nozzle to convert the velocity of the
exhaust steam entering it into pressure.
c an overflow space between both for the purpose of allowing the
steam of the first period first to develop its full velocity, and further
to allow the steam of the second period to take the ordinary way into
the atmosphere or into the condenser.
d a back-pressure valve at the end of the diverging tube to prevent
any steam from the first period after its velocity being converted into
pressure again to take its way back again through the diverging tube to
the overflow.
The exhaust nozzle is to be placed as near as possible to the exhaust
port of the engine, and should not be of less area than the area of the
steam ports.
The bore of the diverging tube generally will be as large as or
slightly larger than the area of the mouth of the exhaust nozzle, for
the purpose of gaining back under pressure as much steam as possible.
In many cases however it might also be of much less bore.
The overflow space and the pipe leading from it are in continual free
communication with either the open air or with the condenser, and its
area being as large or larger than the area of the mouth of the exhaust
nozzle it is evident that the apparatus never can give occasion to an
increase of back pressure in the cylinder.
The working of this pressure restoring apparatus when fitted to an
engine is as follows:-The steam of the first period of exhaust will rush
with great velocity through the exhaust nozzle, and passing the overflow.

page_text: The steam stored up in the air vessel under pressure may be used for
any useful purpose, either for heating or for developing any power, or
for increasing the original engine power.
The construction of the apparatus itself may be varied and modified in
many ways as science and experience will suggest.
Some very useful applications of the apparatus and of the steam
restored under pressure are the following:
1. The steam restored under pressure is used to work another steam
engine, either connected with the original engine or not. The advantage
of this construction, compared with other compound engines, is that the
back pressure from the low-pressure cylinder on the piston of the high-
pressure one is either removed altogether or for a certain period of the
stroke, and both engines are acting as condensing ones by taking the
overflow steam of the first cylinder as well as all the exhaust of the
second cylinder to the condenser.
2. The pressure restoring apparatus may be applied to condensing
engines where water [for condensing purposes is scarce, to discharge part
of the exhaust steam through the back pressure valve into the open air
or into any room, or place, or space when needful, and to take only the
rest of the exhaust through the overflow pipe to the condenser. The
back-pressure valve prevents any air from entering the condenser.
3. The steam restored under pressure may be applied for increasing
the draft in steam boilers by blowing it through a blast pipe into the
chimney. This continuous blast will have a much better effect upon the
draft than if the intermittent action of the exhaust were conveyed
directly from the cylinder into the chimney as usually done.
4. The steam restored under pressure may very usefully work a jet
elevator to force water out of a well, or tank, or an injector to feed a
steam boiler either alone or combined with fresh steam, thus combining
a pump or feeding apparatus with a feed water heater in a most perfect
manner.
5. The steam restored under pressure may very usefully be applied to
produce a partial vacuum on the piston of the engine during the second
period of exhaust by forming the driving jet of a blast vacuum apparatus,
by which the steam remaining in the cylinder after the first period of
exhaust is drawn out of it.

page_text: Figure 1 represents a pressure restoring apparatus and an air vessel
fitted to a steam engine. C is the steam cylinder; a¹, the exhaust pipe
of the cylinder; a, the exhaust nozzle of the apparatus; o, the overflow
space; d, the overflow pipe; b, the diverging tube; c, the back
valve; e, the discharge pipe of the steam, again provided with a certain
pressure; A, the air vessel; n, the outlet pipe of same.
pressure
The working of the apparatus is as follows:-The steam of the first
period or stage of exhaust will be discharged with great velocity out of a
the exhaust nozzle a and enter the diverging tube b, where it converts its,
velocity into pressure sufficient to overcome the resistance of the back-
pressure valve c and to pass into the air vessel A, out of which it may
leave in a continuous stream through the pipe n. As soon as the first
period of exhaust is finished the velocity of the steam in the exhaust
nozzle a will become less, and the corresponding pressure in the
diverging tube not being sufficient to overcome as yet the pressure of
the air vessel the back pressure valve c is shut, and the exhaust steam
will take its way altogether through the overflow d.
This process is
repeated with every new stroke, the steam of the first period of exhaust 3

page_text: always being stored up in the air vessel, and the steam of the second
period being discharged through the overflow.
Figure 2 shews the same arrangement, with the only difference that
the overflow pipe has the direction of the exhaust nozzle, and the
diverging tube 6 is bent off in a right angle to it. The same letters as
those in Figure 1 indicate similar parts. The working of this apparatus
is exactly the same as described above in relation to Figure 1. The
smallest diameter of the diverging tube 6 will generally be as large as
the outlet diameter of the exhaust nozzle or slightly larger; but in
many cases when the intention is not prevailing to gain back under
pressure as much of the exhaust as possible the above diameter may
also be decidedly smaller than the diameter of the exhaust nozzle.
Figure 3 shews a pressure restoring apparatus intended for an engine
of which the slide valve gradually opens the exhaust port. The same
letters as those in Figure 1 represent similar parts. f is the valve
applied to the overflow of the apparatus and worked by the lever g and
the disc h on the main shaft of the engine. The valve f is furnished
with a spiral spring forcing it always back on its seat again when the
protuberances of the disc h do not keep it open.
The working of the apparatus is in the following manner :-The valve
fis shut by the spiral spring shortly before the beginning of the opening
of the exhaust port, and the exhaust steam is thus compelled to pass
the back-pressure valve and to enter through the pipe e into the air
vessel A. As soon as the valve ƒ then is opened by the disc the valve c
will be forced down by the pressure in the air vessel and the exhaust
passes through the overflow either into the atmosphere or into the
condenser. The exact time of the opening of the valve ƒ depends on
the arrangement of the protuberances of the disc, and the opening may
occur after any length of the stroke of the piston being made.
Figure 4 shows a jet condenser, of which the cold water jet is driven
by the steam restored under pressure by the apparatus described in
Figs. 1, 2, & 3. n¹ is the pipe leading the steam from air vessel A
to the condenser; i is the nozzle belonging to this pipe; w is the water
inlet; k, k, the annular water passage into the combining nozzle l;

page_text: d, the pipe conveying the overflow steam to the condenser; m, m, the
annular passage for this steam into the condensing nozzle p; q, the
diverging tube for converting the velocity of the water jet into pressure
to overcome the pressure of the atmosphere; r, the water discharge
pipe.
The working of this condenser is as follows:-The steam coming in a
continuous jet out of the nozzle i also maintains a continuous jet of
water rushing out of the nozzle 7. This water jet will form a steady
vacuum with the overflow steam in the condensing nozzle p, which
vacuum is transferred on the piston of the engine by the pipe d¹. The 1
jet of water converts its velocity into pressure again in the diverging
tube and becomes thus enabled to discharge through the piper not-
withstanding the resistance of the pressure of the atmosphere.
Figure 5 shews a similar apparatus to that shewn in Figure 4, only
the nozzle i is passed through the water nozzle k, k, into the interior of 1
the combining nozzle p, thus giving the water jet an annular sectional
area. The same letters as those in Figure 4 represent similar parts.
The working of the apparatus is also the same as described in relation
to Figure 4, with the difference that the steam from the air vessel A
gives a new impulse to the water jet after the jet having already 2
entered the condensing nozzle p, and being combined with the overflow
steam.
Figure 6 shews the combination of a pressure restoring apparatus with
an ordinary condenser for the purpose of discharging by direct action
the condense water out of the condenser in case of the final pressure in 2
the cylinder being higher than that of the atmosphere. The same letters
as those in Figure 1 represent similar parts. w is the water inlet of the
condenser; S, the condenser; 8, a back pressure valve; t, a communica-
tion pipe. The working of this combination is as follows:-
The exhaust steam of the first period or stage of exhaust converting 3
its velocity into pressure in the diverging tube 6 will shut the valve &
and open the valve c, discharging together with any liquid gathered over
the same out of the pipe e. With the beginning of the second period of
exhaust the internal pressure on the valve c becoming less the pressure

page_text: of the atmosphere will close this valve and the steam will pass through
the overflow pipe d into the condenser S. The same pressure then being
established in the tube 6 and in the condenser the liquid gathered on
the bottom of the latter will open the valve s and enter the space over
the valve c, to be discharged with the next puff.
The pipe 6 may also be provided with a special escape valve for the
steam, as shewn in the Drawing by dotted lines. This valve v is very
useful where the water contains much matter that would be precipitated
and deposited by heating the condense water too much and might easily
choke the valves. The water and the steam escape quite separately
when this arrangement is applied, and the valves will remain clean in
consequence.
Figure 7 shews a similar arrangement, only the pressure restoring
apparatus being intended for a slowly working engine it is provided with
a valve worked by the excentric or disc on the engine shaft, as
described above. By means of the valve the steam is allowed to escape
separately from the water. The working of this apparatus however is
the same as described in relation to Figure 6.
0
Having now described the nature of the said Invention, and in what
) manner the same may be performed, I declare that I claim,—
First. The construction, application, and employment of apparatus,
substantially as described, to gain back again under pressure part of the
exhaust steam of steam engines, as described and illustrated in the
Figures 1, 2, and 3 of the accompanying Drawings.
Secondly. The construction, application, and employment of apparatus
to discharge part of the exhaust steam of condensing engines into the
open air and to take only the remaining part of the exhaust to the
condenser for the purpose of saving condensing water, substantially as
herein-before described.
0 Third. The construction, application, and employment of jet con-
densers, using the steam restored under pressure by the apparatus
illustrated in Figures 1, 2, and 3 by giving a continuous impulse to the
cold water jet, either before it enters the condensing nozzle (Figure 4)
or after the combination of water and exhaust having already been
5 effected (Figure 5).

page_text: Fourth. The combination of pressure restoring apparatus with a con-
denser of any kind, such as to discharge the condense water by direct
action after every stroke of the piston, as herein-before described and
illustrated in Figures 6 and 7.
In witness whereof, I, the said Ernst Körting, have hereunto set 5
my hand and seal, this Twenty-third day of May, in the year of
our Lord One thousand eight hundred and seventy-two.
Witness,
E. SCHLATTER.
E. KORTING. (L.S.)