IMPROVEMENTS IN STEAM ENGINES
Year: 1877

page_text: LETTERS PATENT to Konrad Wilhelm Jurisch, of Widnes, in the County of
Lancaster, Doctor of Philosophy, and John Henry Lewis, of the same Place,
Manager of Chemical Works, for the Invention of "IMPROVEMENTS IN STEAM
ENGINES."
Sealed the 8th March 1878, and dated the 14th September 1877.
PROVISIONAL SPECIFICATION left by the said Konrad Wilhelm Jurisch and
John Henry Lewis at the Office of the Commissioners of Patents on the 14th
September 1877.
KONRAD WILHELM JURISCH, of Widnes, in the County of Lancaster, Doctor of
Philosophy, and JOHN HENRY LEWIS, of the same Place, Manager of Chemical Works.
"IMPROVEMENTS IN STEAM ENGINES."
This Invention relates to our application for Letters Patent dated March 15th,
1877, Number 1028.
In the Specification accompanying our application of that date we claimed to be
able to utilize the whole or nearly the whole of the latent heat contained in the
exhaust steam of an ordinary steam engine.
Further calculations have shewn us that we must create by some means an out-
flow of heat; this we effect by allowing a portion of the steam to escape either into
the air or into a condenser, or into some other apparatus apart from the engine.
We therefore construct our engine in the following manner :- -We convey the
exhaust steam from the working cylinder, at the change of the stroke, into a second
cylinder, which we call the exhausting cylinder, where it becomes expanded in any
desired ratio, thus leaving as indicated effect of the working piston the force
exercised on the piston from the boiler, minus the back pressure caused by the mean
tension of this expanded exhaust steam during its process of expanding.
The piston of the exhausting cylinder has a double action, namely,—
1st. To exhaust the steam from the working cylinder.
2nd. At the same time to compress the exhaust steam from the preceding stroke

page_text: to its original tension, equal to that of the boiler, which will take place at a point
of the stroke depending upon the ratio of expansion used.
The power necessary to press the steam back again into the boiler during the
remainder of the stroke would be exactly equivalent to the indicated effect gained
from the working cylinder, and it therefore follows that only a fraction of the above-
named power will be required (if we dispose of a portion of the exhaust steam
otherwise) for forcing the remaining part only back into the boiler.
We allow the aforesaid portion of the exhaust steam to escape from the exhausting
cylinder in the following manner:-As soon as by the action of the exhausting
piston the steam has been compressed to the tension of the boiler, the valve towards
the boiler may open and remain open until so much of the steam has been forced
back into the boiler as is required, then the valve may be closed simultaneously
with another valve being opened, which allows the remaining portion of the steam
to escape into the air, or into a condenser, or into some other apparatus.
The power necessary for working the exhausting cylinder is derived from a high-
pressure boiler, generating steam of higher pressure than that supplying the working
cylinder; this steam is made to act upon the piston of a high-pressure cylinder (or
we may use two or more cylinders if necessary), the piston rod of which is con-
nected in any suitable way with the piston rod of the exhausting cylinder.
The exhaust steam of the high-pressure cylinder or cylinders may be used in
several different ways, according to circumstances.
1st. It may be allowed to escape directly at the return of each stroke into the
boiler supplying the working cylinder, in which it has to replace that part of the
exhaust steam from the working cylinder, which we have made to escape from the
exhausting cylinder, as above mentioned, and the remainder of it has to condense in
this boiler, and by its liberated latent heat to raise the temperature of the feed
water from its external temperature to that corresponding to the pressure of the
boiler.
2nd. We may treat the high-pressure exhaust steam in the same manner as the
low-pressure exhaust steam, by supplying the high-pressure cylinder with an
exhausting cylinder of its own, and making in an analagous way the difference
between effect gained and power required of the high-pressure apparatus equal to
the difference between effect gained and power required of the low-pressure
apparatus.
The high-pressure boiler may be fed with water from the boiler supplying the
working cylinder.
The ultimate advantage of this engine consists in creating under certain conditions
a greater indicated effect from a certain weight of steam without using any more
feed water, and if required without any water for condensing purposes than can be
obtained by many of the present non-condensing engines.
We have thus described our modes of carrying our Invention into effect, we do
not however confine ourselves strictly to the precise methods mentioned, as we may
alter them according to circumstances without affecting the principles of our Inven-
tion, as for instance, we may allow that portion of the steam which has to escape
into the air or into a condenser, or into any other apparatus, to be abstracted from
the exhausting cylinder at a different period of the stroke from that mentioned, as
may be most profitable with regard to the varying pressures of the boiler supplying
the working cylinder.
The principle of our Invention may be briefly expressed as follows:-We utilize
in returning by means of the power exercised by a high-pressure boiler and pumping
apparatus the whole of the exhaust steam of our engine, minus that portion of it
which has to be abstracted in order to cause a smaller power to be applied by the
high-pressure apparatus for working the exhausting cylinder than we gain from the
working cylinder, and for keeping constant the temperature of the boiler supplying
the working cylinder.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Konrad Wilhelm Jurisch and John Henry Lewis in the Great Seal
Patent Office on the 12th March 1878.
KONRAD WILHELM JURISCH, of Widnes, in the County of Lancaster, Doctor of
Philosophy, and JOHN HENRY LEWIS, of the same Place, Manager of Chemical Works.
"IMPROVEMENTS IN STEAM ENGINES."
The steam from a low-pressure boiler, which in the accompanying Drawing is
denoted by the letter "M," acts, by means of the steam pipe P₁, on the piston of a
steam cylinder "A," which we call the working cylinder. This cylinder is, by the
steam pipe P., in communication with a second cylinder "B," which we call the
exhausting cylinder, in such a way that the latter aspirates the expanded or
expanding exhaust steam from the working cylinder.
The expansion of the exhaust steam may take place either in the working
cylinder alone by means of an early cut-off, as shewn in the Drawing, by the
indicator diagram a, or in both cylinders by suitably arranged motions of the
pistons, or in the exhausting cylinder alone, if it should be preferred to work the
working cylinder with full pressure of steam to the end of the stroke. This
expanded exhaust steam exercises a back pressure on the working piston, and a
forward pressure on the exhausting piston.
From the energy transferred upon the working piston by the low-pressure steam,
and the back pressure exercised by the expanded exhaust steam, the indicated effect
of the working cylinder is derived; this being at the same time the indicated
effect "E" of our engine.
The piston of the exhausting cylinder has a double action,-
1st. To exhaust the steam from the working cylinder.
2nd. At the same time to compress the exhaust steam from the preceding stroke
to its original tension, equal to that of the "M" boiler. As soon as, during the process
of compressing, the tension of the condenser or of the atmosphere is reached a
certain portion of the steam, which in the Drawing is denoted by the figure upon
the indicator diagram b, is escaping to the outside of the cylinder by means of a
valve "D" which we call the difference valve, and a measure box X; the remaining
portion of the steam (1 - ½) then being compressed to the tension of the "M" boiler,
and in that state forced back into the "M" boiler by means of the steam pipe P.
In the accompanying Drawing of a non-condensing engine the expansion in the
working cylinder goes down to one atmosphere, consequently the above-mentioned
of the steam is allowed to escape, in this particular case, at the beginning of the
stroke of the exhausting piston. Thus the difference valve D has to remain open
until the exhausting piston has reached the position S₁. During the travel from
the position S, to position S, the 1 - 1 of the steam becomes compressed to the
tension of the M boiler, the difference valve D being closed. During the remainder
of the stroke the difference valve D opens from P, to P, thus allowing the com-
pressed 1 of the steam to be forced back into the M boiler.
-
If no steam were allowed to escape, i.e. in those cases when = 0, the power
necessary for working the exhausting piston would theoretically be exactly equal to
the effect E of our engine gained from the working cylinder. It therefore follows
that only a smaller power than E is required for working the exhausting piston in
all cases where is greater than nought. In the particular case shewn in the
accompanying Drawing, and in all similar cases, the power indicated as being
required for working the exhausting piston amounts to E (1 ½).
-
The power necessary for working the exhausting cylinder is derived from a high-
pressure boiler "H" generating steam of higher pressure than the M boiler. This
stean, through the pipe P, is made to act upon the piston of a high-pressure

page_text: cylinder C, the piston rod of which is connected in any suitable way with the piston
rod of the exhausting cylinder. In the Drawing the simplest manner is shewn by
a through-going piston rod.
The exhaust steam of the high-pressure cylinder may be used in several different
ways, according to circumstances:-
1st. It may be allowed to escape directly at the return of each stroke into the
boiler supplying the working cylinder (M boiler), in which it has to replace that
portion of the exhaust steam from the working cylinder, which we have made to
escape from the exhausting cylinder, viz., that, as above mentioned; and the
remainder of it has to condense within this boiler to water of the temperature of
the boiler, and, by its liberated latent heat, to raise the temperature of the feed
water from its external temperature to that of the boiler, thus keeping constant the
temperature and the tension of the "M" boiler, which consequently does not require,
in this case, any application of heat from the outside if the loss by radiating heat
is left out of regard.
2nd. If it should be preferred to apply a certain amount of heat to the "M" boiler,
for instance, just as much as is necessary for raising the temperature of the feed
water from its external temperature to that of the "M" boiler, the exhaust steam
from the high-pressure cylinder would only be called upon to replace that of the
steam which has escaped to the outside of the system. As by the function of the
exhausting cylinder, together with the above-mentioned replacement of the of
the steam which has escaped to the outside, the steam necessary for the working
cylinder becomes regenerated, we have found it convenient to call our engine by the
name regenerative steam engine.
3rd. We may use the exhaust steam from the high-pressure cylinder for any
other purpose extraneous to the engine described.
The high-pressure boiler may be fed with water from the low-pressure boiler by
means of the feed pump S
45
In the accompanying Drawing the ½ of the steam which has to escape is represented
as being conveyed through the pipe P₁ (which for convenience of Drawing is shewn
broken off when leaving the difference valve D, and re-produced as P. near the
measure box X), and as entering into a measure box X, from where as soon as the
difference valve D is closed it passes, together with a spray of water from the
reservoir R, into the small open water basin Z, from which the M boiler is fed by
means of the feed pump S. The water to be used at each stroke is regulated to
be of so small a quantity that it may become heated to about the boiling point,
thus allowing of a feeding with boiling or nearly boiling water.
The of the steam, if circumstances permit, might also escape directly from the
difference valve D into the open air, or into a condenser, or into some other
apparatus. The of the steam may also be abstracted from the exhausting cylinder,
or from the system in general, at a different period of the stroke, or of the circuit,
from that mentioned, as may be most profitable with regard to the varying
circumstances.
After having thus described our modes of carrying our Invention into effect we
have to declare however that we do not confine ourselves strictly to the precise
methods mentioned, but that we may alter them according to circumstances without
affecting the principle of our Invention. And we would further add that the
Drawing accompanying this Specification is simply an illustration of the principle
of our Invention, and that we do not bind ourselves to the particular proportions
and mechanical details thereon shewn, as the same would vary according to the
pressures used, and other conditions.
The advantages of our regenerative engine in comparison with the present
expansive engines are chiefly the following-Our engine permits the use of steam
of very bigh pressure (the higher the pressures of both boilers, within practical
limits, the more profitable our engine becomes), and at the same time the applica-

page_text: tion of a very high ratio of expansion, for we cause the steam to expand in two
stages :-
Firstly. It expands within the high-pressure cylinder from the tension of the
"H" boiler to that of the "M" boiler, as shewn in the indicator diagrain "C," or to any
other tension desirable, according to the purpose for which the high-pressure exhaust
steam is used. At the end of this first stage of expansion if returned to the "M"
boiler the steam becomes converted into the saturated state by the processes within
the "M" boiler without requiring any more heat from the outside.
Secondly. It expands in the working cylinder from the tension of the "M" boiler
to that of the atmosphere or of the condenser.
By these means we avoid those practical obstacles which have hitherto limited
the ratio of expansion, and are enabled, without using any extra heat, to carry the
expansion to a higher ratio than has hitherto been considered practicable; and
besides, we have the advantage that we generate the necessary quantity of steam at
less expense of heat, as we are feeding the H boiler with water from the "M" boiler.
The principle of our Invention in shortest words is the following-We utilize in
returning by means of the power exercised by a high-pressure boiler, and high-
pressure apparatus, the whole of the exhaust steam of our engine, minus that
portion of it which has to be abstracted (i.e., 1 ), in order to cause a smaller
power to be applied by the high-pressure apparatus than we gain from the working
cylinder, or for making within the low-pressure boiler room for the high-pressure
exhaust steam, and for keeping thus constant the temperature and the pressure
within the low-pressure boiler supplying the working cylinder.
-
In witness whereof, we, the said Konrad Wilhelm Jurisch and John Henry
Lewis, have hereunto set our hands and seals, this Seventh day of March,
in the year of our Lord One thousand eight hundred and seventy-eight.
KONRAD WILHELM JURISCH. (LS.)
JOHN HENRY LEWIS.
(L.S.)