IMPROVEMENTS IN MARINE STEAM ENGINES AND SURFACE CONDENSERS
Year: 1866

page_text: LETTERS PATENT to Alexander Crichton, of Cork, Ireland, Engineer, for
the Invention of "IMPROVEMENTS IN MARINE STEAM ENGINES AND SURFACE
CONDENSERS."
Sealed the 20th November 1866, and dated the 21st May 1866.
PROVISIONAL SPECIFICATION left by the said Alexander Crichton at
the Office of the Commissioners of Patents, with his Petition, on the
21st May 1866.
I, ALEXANDER CRICHTON, of Cork, Ireland, Engineer, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN MARINE STEAM ENGINES
AND SURFACE CONDENSERS," to be as follows:-
Instead of employing a surface condenser either in the form of a tubular or
tubulous box or boxes or other form or description of vessels mounted upon or
forming part of the engine for receiving the exhaust steam of marine steam
engines, and condensing it for the purpose of adding to the useful effect of the
steam within the steam cylinders, and also instead of employing as part of a
marine steam engine a pump for producing the necessary.circulation of the
condensing water through the surface condenser, I by my present Invention
am enabled to dispense with both of these parts of a surface condensing
marine steam engine, and I simplify the mechanical construction of such
engines, reduce the number of working parts and the liability to leakages

page_text: carry
incident to surface condensers, and economise the power of the engine. I
the exhaust steam from the engine or engines in a metallic pipe or
pipes through the bottom, side, or bilge of the ship externally under the light
load line of flotation, and return it or them through the bottom or side of
the ship to the engine or engines, the external surface of such pipe or pipes
exposed to the cold water through which the ship is being propelled being of
sufficient area to partially or wholly condense the steam.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexander Crichton in the Great Seal Patent Office on the
21st November 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
CRICHTON, of Cork, Ireland, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of May, in the year of our Lord One
thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Alexander Crichton, Her special licence that I, the said Alexander
Crichton, my executors, administrators, and assigns, or such others as I, the
said Alexander Crichton, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 "IMPROVEMENTS IN
MARINE STEAM ENGINES AND SURFACE CONDENSERS," upon the condition (amongst
others) that I, the said Alexander Crichton, my executors or administrators, 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 Alexander Crichton, 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 and accompanying Sheet of Drawings:-
Instead of employing a surface condenser either in the form of a tubular
or tubulous box or boxes or other form or description of vessels mounted upon

page_text: or forming part of the engine for receiving the exhaust steam of marine steam
engines, and condensing it for the purpose of adding to the useful effect of
the steam within the steam cylinders, and also instead of employing as part
of a marine steam engine a pump for producing the necessary circulation of
the condensing water through the surface condenser, I by my present
Invention am enabled to dispense with both of these parts of a surface con-
densing marine steam engine, and I simplify the mechanical construction of
such engines, reduce the number of working parts and the liability to leakages
incident to surface condensers, and economise the power of the engine. I
carry the steam from the eduction pipe of each cylinder to a metallic pipe
or tube which passes out of the ship through the bottom, side, or bilge
externally from or near that portion of the ship in which the engines are
fitted
away aft sufficiently far to effectively condence the steam, and the fresh
water resulting from the condensation of the steam is carried back inboard,
the pipe or conduit being connected to the foot of the air pump or pumps
or wherever inboard may be found most convenient for collecting the water
and utilizing the vacuum produced by the condensation of the steam.
In practically applying my Invention I prefer to adopt rectangular tubes
or conduits for conveying the exhaust steam from the engines, and to take
advantage of the opportunity afforded for heating the feed water required for
supplying the boilers by interposing between the exhaust nozzle of each engine
and the external condensing tube a hollow, double, tubular or tubulous vessel,
by which the exhaust steam is made to impart some portion of its heat to the
feed water in its passage to the boiler.
In the accompanying Sheet of Drawings I have shown views of a mode of
applying my Invention to a pair of engines on board of a screw steamship,
Fig. 1 being a plan of the steam engines and the condenser apparatus, pumps,
and other parts connected therewith; Fig. 2, a cross section of Fig. 1 ; and
Fig. 3 an external elevation or side view of the vessel showing the position of
the condensing pipes.
The pair of marine screw engines shown in Figs. 1, 2, 3, are as to their
general arrangement such as are commonly employed for actuating a screw
propellor in mercantile steam ships, having been altered and added to in
accordance with my Invention.
In Figs. 1 and 2, A is the bull of the ship; B, the foundation of the
engines; C, C, the cylinders; D, the original air pump; E, the original and
ordinary injection condenser, hot well, and the apparatus belonging thereto; F,
the air vessel.
The following smaller letters of reference relate more particularly, though

page_text: not exclusively, to the several novel parts or novel arrangements and dis-
positions of parts in accordance with my Invention, that is to say, a, a, are
the doors or stop plates by which the connection between the steam exhaust
passage of each cylinder and the ordinary central injection condenser is shut
off; b, b, combined eduction pipes and feed water heaters placed between the
cylinders and the surface condensers or the condensing pipes; C, C, screw
double-stop valves applied to the outer end of each eduction pipe, and so
arranged that when the top valve is closed and the bottom one open the
steam passes into the surface condenser or condensing pipes, and when the
bottom valve is closed and the top one open the engine can be worked as a
non-condensing engine by exhausting through the exhaust discharge pipes
(d, d), and by closing both the upper and lower valve in case of accident to
the surface condenser and removing the doors or stop plates (a, a,) the ordinary
injection condenser can be brought into use; d, d, exhaust discharge pipes
extending upwards to discharge the uncondensed steam externally at a con-
venient part of the ship's side above the deep load line; e, e, cross section of
surface condenser pipes on each side of the vessel, which extending along the
outside of the ship, and shown in Fig. 3 as passing through the screw pro-
peller opening, are made to return along the other side of the ship where they
terminate inboard, as shown in Fig. 2, in connection with shut-off valves; f,f,
shut-off valves introduced between the further end of each surface condenser
pipe, and the ordinary injection condenser for shutting off communication
between them in the event of an accident happening to the surface condenser or
the parts thereof external or internal to the hull of the ship; 9, 9, junction pipes
connecting the surface condenser pipes with the common injection condenser
through the shut-off valves (f,f); h, h, the suction pipes of the feed pumps;
j, j, feed water heaters, which in this case are shown as jackets to the eduction
pipes, the air pump chamber, which has been reduced to one-half of its
original capacity, inasmuch as that consequent on the application of the
surface condensing apparatus, according to my Invention, a great reduction in
the capacity of the air pump and in the power required to actuate it is
effected.
I have shown in the accompanying Drawing, at Figs. 1 & 2, the dimen-
sions, proportions, and general arrangements of parts of the engines and the
surface condensing apparatus connected therewith in accordance with my
Invention, which in practice I have found to be suitable, and several parts or
portions of such Figures are drawn to the same scale as therein shown, and
in Fig. 3 the general arrangement of the surface condensing pipes external
to the ship are drawn to a smaller scale as there shown; but I wish it to

page_text: be understood that I do not confine myself to the dimensions, nor to the pro-
portions of the several parts in relation to each other, as it is evident they
may and should be changed according to the requirements or circumstances of
each particular application; as, for instance, when the engines are placed
nearer to the stern of the ship and the same quantity of steam has to be passed
through the condensing pipe or pipes, the length of the latter being reduced
by such change of position, their sectional area must be proportionately increased
that the cooling or heat abstracting surface may be maintained at its full
efficiency under the most unfavorable conditions.
The condensing pipes placed externally to the ship's hull may be of copper,
of wrought iron plain, tinned, galvanized, or otherwise coated to prevent
oxidation, or of cast iron or other metal, and in shape they may be of a
regular round, oval, square, or paralelogram in cross section, or be corrugated
so as to present the largest surface for a given dimension of cross section, and
I prefer to fasten them to the ship's sides by means of clips, bands, or hoops,
although any other convenient mode of fastening may be adopted.
The contruction of the feed water heater as well as its disposition in
relation to the exhaust nozzle or opening and the condenser pipes, as also the
mode of constructing and connecting the compound valves by which the course
of the exhaust steam may be varied, modified, or changed to suit each
particular case; for although I have shown in Figs. 1 & 2 the feed water
beater as a jacketed pipe the steam within and the feed water passing around
the annular space between the external surface of the pipe and the internal
surface of the jacket, it may be constructed as a case or vessel, with a
series of tubes therein; moreover, the double-action valves shown in the
Drawings may be compound valves, and be operated together or seperately.
As it is self-evident that by the reduction of the capacity of the air pump less
of the power of the steam engines is required by the use or employment of a
surface condenser apparatus according to my Invention, it follows that economy
of power is the result of the employment of the surface condensing arrangement
as shown on the Drawing and herein-before described.
Having now described my Invention of "Improvements in Marine Steam
Engines and Surface Condensers," and illustrated the same by the several
Figures in the accompanying Sheet of Drawings, I wish it to be understood
that I do not claim as novel those parts of the general arrangement of the
double cylinder direct-acting screw engines indicated by the capital letters
B, C, D, E, F, in Figs. 1 & 2 in the accompanying Drawing, which relate
to those parts of the original engines which remain unaltered, and to which
the improvements constituting my Invention are added, or in which (as in

page_text: the case of the air pump chamber) alterations are made for the purpose of
adapting them in accordance with my Invention to the other parts thereof;
but what I do claim is,-
First, the improvements in marine steam engines and surface condensers
herein described and as illustrated in the accompanying Sheet of Drawings
by the smaller letters of reference employed to denote those parts of the
Figures 1 & 2.
.
Second, the use or employment of metallic tubes in the manner herein
described for condensing the exhaust steam of marine steam engines without
the aid of a cold water circulating pump or pumps, and economising fuel on
board of steam ships.
Third, the combination of a metallic surface condensing tube as herein
described, fitted or applied, as described and illustrated, with a feed water
heater interposed or applied between the exhaust nozzle or passage of the
steam cylinder and the shut-off valve or connection of the condensing pipe
external to the vessel, for the purpose of effecting economy in the consumption
of fuel.
Fourth, the mode or method herein described and illustrated in the accom-
panying Drawing for changing the direction of motion or passage of the
exhaust steam after it leaves the steam cylinder so as to admit of the steam
being discharged uncondensed, or discharged into the metallic tube surface
condenser or into the ordinary injection condenser when such changes may
become necessary from accident or other cause.
Fifth, the mode or method herein described of adapting marine steam
engines having an ordinary injection condenser or condensers to the use or
employment of an external metallic tube surface condenser as herein described,
and by which the necessity for cold water circulating pumps is avoided, and
the power required to work them is saved.
In witness whereof, I, the said Alexander Crichton, have hereunto set my
hand and seal, this Twentieth day of November, in the year of our
Lord One thousand eight hundred and sixty-six.
ALEXANDER CRICHTON. (L.D.)