IMPROVEMENTS IN STEAM ENGINES
Year: 1856

page_text: LETTERS PATENT to Constant Jouffroy Duméry, of Paris, in the Empire
of France, Civil Engineer, for the Invention of "IMPROVEMENTS IN STEAM
ENGINES
Sealed the 24th February 1857, and dated the 4th September 1856.
PROVISIONAL SPECIFICATION left by the said Constant Jouffroy
Duméry at the Office of the Commissioners of Patents, with his
Petition, on the 4th September 1856.
I, CONSTANT JOUFFROY DUMERY, of Paris, in the Empire of France, Civil
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN STEAM ENGINES," to be as follows:-
Present attention to steam as a motive power is directed by recent scientific
research and experience to the economy and economical advantages resulting
from the employment of highly heated and therefore dilated steam, air, or
gases, and many attempts have already been made with a view to its practical
application. Heretofore steam has sometimes been surcharged with heat in its
passage to but previous to its admission into the engine, and at others the
steam has been generated at once at a high pressure and high temperature in
small tubes or worms, while at other times, again, a jet of anhydrous steam has
been injected into aqueous steam, and, lastly, some attempts have been made
to work the same volume of steam condensed and expanded alternately.
Each of these various systems I believe to be attended with more or less

page_text: difficulty and inherent danger:-1st, that of keeping a large volume of steam
at a high temperature and great pressure; 2nd, the difficulty of obtaining a
regular supply when steam has to be submitted to the conditions of extreme
heat; 3rdly, the difficulty of obtaining any additional heat except in a very
ordinary degree, whereas important results may be arrived at; 4thly, and
lastly, the loss sustained in the benefits afforded by the very principle of
additional and highly heated steam consequent on the capaciousness of the
reheating cylinders or vessels.
Now, in order to secure good practical results, I believe the three con-
ditions it is essential to fulfil are:-1st, to generate aqueous steam in the best
known apparatus, provided with water and steam chambers; 2ndly, to render
the same aqueous steam anhydrous by means of special apparatus; and,
3rdly, to heat highly or surcharge with heat the volume of steam only that is
required for each stroke of the piston to a degree in proportion to what may
be required. These three conditions may be fulfilled by the employment of a
vessel whose capacity is equal to the amount of steam to be spent at every
stroke, which capacity should be interposed between the ordinary steam
generator and the extra heating apparatus with this vessel, although the
working may be more practicable, yet it is probable that the capacity of the
vessel would prove to be not simply passive but prejudicial. The most
important and complete result seems to me to be attainable by effecting the
surcharge or extra heating after the steam has previously expended itself in a
first and suitable cylinder. Thus, supposing steam to be introduced at any
pressure, say, at six atmospheres, for instance, into the said first cylinder,
there to work either at a high uniform pressure or with a little expansion;
if, now, this steam, after acting in this first cylinder, be let, into. a second
cylinder, there to expand, as is the case in Woolff's engines, but which should
be compelled, in its progress between the first and smaller cylinder and the
second and larger. cylinder to go through a chamber or apparatus, there to
receive additional heat and pressure, in which it will acquire only a known or
given volume. Thus the properties of dessiccation, dilatation, and pressure,
or volume, if required, may be attained without any possibility of the occur-
rence of the above-mentioned mishaps. The regulation of the power. will
prove as easy with this as with ordinary aqueous steam engines, as it can be
effected at the first induction, or, still better, by the first cut-off. The working
of an engine on this principle will be equally as simple as an ordinary steam
engine, and at the same time effect considerable saving, for with an increase
of fuel, comparatively trifling, double the amount of effective work may be
obtained.

page_text: As regards the application of my principle, many different ways are open.
Steam may be highly heated, for instance, either by a fire-place specially for
the purpose, or by merely conducting the heat from the ordinary furnace to
the point required. The same arrangements for working the steam will hold
good for existing engines or others constructed for the purpose.
In existing engines with one cylinder, by the application of a second
cylinder, either smaller, for the purpose of supplying the pre-existing cylinder,
which now becomes the expansive cylinder, or larger, if the existing cylinder
be purposed to supply the cylinder added as the expansive cylinder; in either
case I place the apparatus for imparting additional heat or surcharging the
steam with heat between the two cylinders; according to the former method
or arrangement a saving will result in the daily expense, and from the latter
an increased power will be obtained with the same expense.
In existing engines with two cylinders, and in order to prevent their being
overworked, a cut-off may be contrived in the smaller cylinder for the purpose
of diminishing the steam pressure, thereby reducing it to half its pressure, &
to what it is required to be on its induction into the larger cylinder. The
extra heating apparatus will, however, in all cases be placed between the two,
and with this advantage, that at a less expense the same effective work will
.be obtained; and for such engines, the parts of which can sustain a greater
pressure, the smaller cylinder may be reduced to half its capacity, while the
steam maintains an equal pressure throughout the stroke, but on its being
admitted into the larger cylinder, or after receiving additional heat from the
heating apparatus, the said pressure becomes about double that which it would
have been had not the steam been charged with extra heat in its progress
through the surcharging or extra heating apparatus; hence again an increase
of power with the same expense.
For an engine with several cylinders working simultaneously on one and
the same shaft, but independent of one another as regards the feeding or
supplying steam, I increase or diminish the capacity of any of the cylinders
according to the result it is desired to obtain, and I form between them a
steam passage, in which I place a surcharging or heating apparatus between
cach cylinder.
Finally, I construct engines specially to work according to my Invention,
and of the most suitable proportions, wherein a considerable expansion may
be attained with a rise of temperature comparatively moderate.
In the above mentioned instances the proportions proposed (half) as a
base, I wish it to be understood that this proportion may be varied without
departing from the principle of my Invention. In addition to the economy

page_text: in working, my improved engines have great regularity of motion and softness
of emission. Steam does not, as in Woolff's engines, spring up to the larger
cylinder with its utmost pressure, but with a pressure next to that which it
had in the smaller cylinger before it was highly heated; the whole amount of
heat being attained only after a complete stroke of the smaller cylinder, the
increase of volume will be gradual and continuous.
These engines will produce the maximum of effect with the combination of
the smaller cylinder, such that it accomplishes its revolution within the time
necessary for the greater cylinder to perform any given part of its own, and
according to the extent of expansion it is desired to obtain, that is to say,
during the half or fourth, &c. part of the stroke. In this case, if the process
of the smaller cylinder were were continuous, the engine should have several
large cylinders fed alternately by the smaller one; and in case it were desired
to have but one large cylinder, the small cylinder should then have an inter-
mittent motion, viz, to complete its whole stroke within the same time as the
period for admitting steam to the greater cylinder, and then remain at rest
till the larger cylinder has accomplished its entire stroke.
One of the principal difficulties and hindrances to the use of steam at a
high temperature is the lubrification of the working parts. In order that
the lubrication may not be an obstacle to the use of steam, dried by an
excessive heat, and, above all, that the same steam may be condensed in
closed condensers, that is, in condensers effecting condensation by external
application, in which the fatty matters generally used for that purpose are
an obstacle thereto, I make use of lubricating bodies of mineral substances
which I apply in one or both of the piston plates or rings. I make the rings
sufficiently thick for two series of holes being bored through their periphery
in a position to overlap or break join with each other. Into each hole I
insert small cylinders or blocks of talc or plumbago either in a hard solid state
or of a more friable nature; these cylinders or blocks are pressed upon by
springs, so as to be always pressed in contact with the inside surface of the
steam cylinder. I make use of a similar application for lubricating the piston
rods in their stuffing boxes.
Fig. 1 is an elevation of a horizontal steam engine, its framing and parts
of detail being removed. The heating flue for surcharging the steam with
heat is shown in section. Fig. 2 is a plan of the same, showing the extra
heating flue in section; Fig. 3 is an end view of the cylinders with the
extra heating flue shown in section. In these three Figures similar letters of
reference denote like parts where they recur in the several Figures. A is
a small cylinder receiving steam from the ordinary generator; B, a large

page_text: cylinder, in which expansion takes place; C, a chamber, leading steam from
the smaller cylinder to the larger one. This flue is here represented as single,
but preferably it should consist of a number of pipes, which increase the
heating surface and occupy less space. D, flues, into which the chamber C
is placed. The said chamber or number of pipes may be placed according to
the nature of the fire-place, and be laid on that part which is more directly
heated by the flames, but it is here represented in the flue or chamber into
which the beat and flame first issues from the generator, but may, as above
specified, be inserted into a flue leading from a fire-place specially for the
purpose. E, the generator; F, a reheater of the generator E; G, the brick-
work. Fig. 4 is a plan, partly in section, of a metallic piston of a steam
engine furnished with a mineral lubricator; Fig. 5 is a side view of the same
piston.. In these two Figures similar letters represent like parts. H is the
piston plate; I, the metallic packing; J, J, J, plumbago cylinders; K, spring,
pressing against the cylinder J from the centre towards the periphery; L,
stoppers, securing the springs. Fig. 6 is a section of the lubricator of a piston
rod; Fig. 7 is a side view of the same Figure. In both Figures similar
letters represent like parts. M is the collar of the stuffing box; N, N, N,
the plumbago or talc cylinders; O, springs, forcing the cylinder N against the
piston rod; P, stopper, securing springs 0, 0, 0.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Constant Jouffroy Duméry in the Great Seal Patent
Office on the 3rd March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CONSTANT
Jouffroy Dumery, of Paris, in the Empire of France, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Iler Letters
Patent, bearing date the Fourth day of September, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Constant Jouffroy Dumery, Her special licence that I, the said
Constant Jouffroy Dumery, my executors, administrators, and assigns, or such
others as I, the said Constant Jouffroy Dumery, 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

page_text: 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 "IMPROVEMENTS IN STEAM ENGINES," upon the condition (amongst
others) that I, the said Constant Jouffroy Dumery, my executors or admi-
nistrators, by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe and ascertain the nature of the
said Invention, 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 Constant Jouffroy Dumery, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Sheet of Drawings here-
unto annexed, and to the letters and Figures marked thereon (that is to
say):-
Present attention to steam as a motive power is directed by recent scientific
research and experience to the economy and economical advantages resulting
from the employment of highly heated and therefore dilated steam, air, or
gases. Many attempts have already been made with a view to its practical
application. Heretofore steam has sometimes been surcharged with heat in
its passage to but previous to its admission into the engine, and at others the
steam has been generated at once at a high pressure and high temperature in
small tubes or worms, while at other times, again, a jet of anhydrous steam has
been injected into aqueous steam, and, lastly, some attempts have been made
to work the same volume of steam condensed and expanded alternately.
Each of these various systems I believe to be attended with more or less
difficulty and inherent danger:-1st, that of keeping a large volume of steam
at a high temperature and great pressure; 2nd, the difficulty of obtaining a
regular supply when steam has to be submitted to the conditions of extreme
heat; 3rdly, the difficulty of obtaining any additional heat except in a very
ordinary degree, whereas important results may be arrived at; 4thly, and
lastly, the loss sustained in the benefits afforded by the very principle of
additional and highly heated steam consequent on the capaciousness of the
reheating cylinders.
Now, in order to secure good practical results, I believe the three con-
ditions it is essential to fulfil are:-1st, to generate aqueous steam in the best
known apparatus, provided with water and steam chambers; 2ndly, to render
the same aqueous steam anhydrous by means of special apparatus; and, 3rdly,

page_text: to heat highly or surcharge with heat the volume of steam only that is required
for each stroke of the piston to a degree in proportion to what may be required.
These three conditions may be fulfilled by the employment of a vessel whose
capacity is equal to the amount of steam to be spent at every stroke, which
capacity should be interposed between the ordinary steam generator and the
extra heating apparatus; with this vessel, although the working may be more
practicable, yet it is probable that the capacity of the vessel would prove to be
not simply passive but prejudicial. The most important and complete result
seems to me to be attainable by effecting the surcharge or extra heating only
after the steam has previously expended itself in a first and suitable cylinder.
Thus, supposing steam to be introduced at any pressure, say, at six atmo-
sherės, for instance, into the said first cylinder, there to work either at a high
uniform pressure or with a little expansion; if, now, this steam, after
acting in this first cylinder, be let into a second cylinder, there to expand,
as is the case in Woolff's engines, but which should be compelled, in
its progress between the first and smaller cylinder and the second and
larger cylinder, to go through a chamber or apparatus, there to receive
additional heat and pressure, in which it will acquire a known or given
volume. Thus the properties of desiccation, dilatation, and pressure, or volume
required may be attained without any possibility of the occurrence of the
above-mentioned mishaps. The regulation of the power will prove as easy
with this as with ordinary aqueous steam engines, as it can be effected at the
first induction, or, still better, by the first cut-off. The working of an engine
on this principle will be equally as simple as an ordinary steam engine, and at
the same time effect considerable saving, for with an increase of fuel, com-
paratively trifling, double the amount of effective work may be obtained.
As regards the application of my principle, many different ways are open.
Steam may be highly heated, for instance, either by a fire-place specially for
the purpose, or by merely conducting the heat from the ordinary furnace to
the point required. The same arrangements for working the steam will hold
good for existing engines or others constructed for the purpose.
In existing engines with one cylinder, by the application of a second
cylinder, either smaller, for the purpose of supplying the pre-existing cylinder,
which now becomes the expansive cylinder, or larger, if the existing cylinder
be purposed to supply the cylinder added as the expansive cylinder; in
either case I place the apparatus for imparting additional heat or surcharging
the steam with heat between the two cylinders; according to the former
method or arrangement a saving will result in the daily expense, and from
the latter an increased power will be obtained with the same expense.

page_text: In existing engines with two cylinders, and in order to prevent their being
overworked, a cut-off may be contrived in the smaller cylinder for the purpose
of diminishing the steam pressure, thereby reducing it to half its pressure,
and to what it is required to be on its induction into the larger cylinder. The
extra heating apparatus will, however, in all cases be placed between the two,
and with this advantage, that at a less expense the same effective work will
be obtained; and for such engines, the parts of which can sustain a greater
pressure, the smaller cylinder may be reduced to half its capacity, while the
steam maintains an equal pressure throughout the stroke; but on its being
admitted into the larger cylinder, or after receiving additional heat from the
heating apparatus, the said pressure becomes about double that which it
would have been had not the steam been charged with extra heat in its
progress through the surcharging or extra heating apparatus; hence, again,
an increase of power with the same expense.
For an engine with several cylinders working simultaneously on one and
the same shaft, but independent of one another as regards the feeding or
supplying steam, I increase or diminish the capacity of any of the cylinders
according to the result it is desired to obtain, and I form between them a
steam passage, in which I place a surcharging or heating apparatus between
each cylinder.
Finally, I construct engines specially to work according to my Invention,
and of the most suitable proportions, wherein a considerable expansion may
be attained with a rise of temperature comparatively moderate.
In the above mentioned instances, the proportions proposed (half) as a
base, I wish it to be understood that this proportion may be varied without
departing from the principle of my Invention. In addition to economy in
working, my improved engines have great regularity of motion and softness
of emission. Steam does not, as in Woolff's engines, spring up to the larger
cylinder with its utmost pressure, but with a pressure next to that which it
had in the smaller cylinder before it was highly heated. The whole amount of
heat being attained only after a complete stroke of the smaller cylinder, the
increase of volume will be gradual and continuous.
These engines will produce their maximum of effect with the combination
of the smaller cylinder, such that it accomplishes its revolution within the
time necessary for the greater cylinder to perform any given part of its own,
and according to the extent of expansion it is desired to obtain, that is to say,
during the half, third, or fourth, &c. part of the stroke. In this case, if the
progress of the smaller cylinder were continuous, the engine should have
several large cylinders fed alternately by the smaller one. And in case it

page_text: were desired to have but one large cylinder, the small cylinder should then
have an intermittent motion, viz, to complete its whole stroke within the
same time as the period for admitting steam to the greater cylinder, and then
remain at rest till the large cylinder has accomplished its entire stroke.
One of the principal difficulties and hindrances to the use of steam at a
high temperature is the lubrification of the working parts. In order that
the lubrication may not be an obstacle to the use of steam dried by an
excessive heat, and, above all, that the same steam may be condensed in
closed condensers, that is, in condensers effecting condensation by external
application, in which the fatty matters generally used for that purpose are an
obstacle thereto, I make use of lubricating bodies of mineral substances, which
I apply in one or both of the piston plates or rings. I make these rings
sufficiently thick for two series of holes being bored through their periphery
in a position to overlap or break joint with each other. Into each hole I
insert small cylinders or blocks of talc or plumbago, either in a hard solid
state or of a more friable nature; these cylinders or blocks are pressed upon
by springs, so as to be always pressed in contact with the inside surface of
the steam cylinder. I make use of a similar application for lubricating the
piston rods in their stuffing boxes.
Fig. 1 is an elevation of a horizontal steam engine, its framing and parts
of detail being removed. The heating flue for surcharging the steam with
heat is shown in section. Fig. 2 is a plan of the same, showing the extra
heating flue in section.. Fig. 3 is an end view of the cylinders with the
heating flue shewn in section. In these three Figures similar letters of
reference denote like parts where they recur in the several Figures. A is
a small cylinder receiving steam from the ordinary generator; B, a large
cylinder, in which expansion takes place; C, a chamber, leading steam from
the smaller cylinder to the larger one. This flue is here represented as single,
but, preferably, it should consist of a number of pipes, which increase the
heating surface and occupy less space. D, flues into which the chamber C is
placed. The said chamber or number of pipes may be placed according to
the nature of the fire-place, and be laid on that part which is more directly
heated by the flames, but it is here represented in the flue or chamber into
which the heat and flame first issues from the generator, but may, as above
specified, be inserted into a flue leading from a fire-place specially for the
purpose. E, the generator; F, a reheater of the generator E; G, the brick-
work. Fig. 4 is a plan, partly in section, of a metallic piston of a steam engine
furnished with a mineral lubricator. Fig. 5 is a side view of the same piston.
In these two Figures similar letters represent like parts. H is the piston

page_text: plate; I, the metallic packing; J, J, J, plumbago cylinders; K, spring,
pressing against the cylinder J from the centre towards the periphery; L,
stoppers, securing the springs. Fig. 6 is a cross section of the lubricator of a
piston rod. Fig. 7 is a side view of the piston rod & vertical section of
the same Figure. In both Figures similar letters represent like parts. M is
the collar or gland of the stuffing box; N, N, N, the plumbago or talc
cylinders; O, springs, forcing the cylinder N against the piston rod; P, stopper
or plug, securing springs O, O, O.
Having described the nature of my Invention, and the manner in which
the same is to be performed, I wish it to be understood that what I claim as
my Invention, and desire to be protected by the herein-before in part recited
Letters Patent, is,-
First, using steam surcharged with heat in measured portions (that is to
say), surcharging a cylinder or vessel full at a time in obtaining motive power
by means of steam engines, as herein-before described.
Secondly, I claim the mineral lubricator herein-before described.
And, thirdly, I claim the arrangement of engine herein-before described,
for working steam surcharged with heat in measured portions or quantities.
In witness whereof, I, the said Constant Jouffroy Duméry, have here-
unto set my hand and seal, this Twenty-sixth day of February, in the
year of our Lord One thousand eight hundred and fifty-seven.
C. J. DUMERY. (L.S.)