CERTAIN IMPROVEMENTS IN MARINE STEAM ENGINES
Year: 1860

page_text: LETTERS PATENT to Francis Davidson, of Liverpool, in the County of
Lancaster, Engineer and Boiler Maker, for the Invention of "CERTAIN
IMPROVEMENTS IN MARINE STEAM ENGINES."
Sealed the 7th February 1861, and dated the 8th August 1860.
PROVISIONAL SPECIFICATION left by the said Francis Davidson at the
Office of the Commissioners of Patents, with his Petition, on the 8th:
August 1860.
I, FRANCIS DAVIDSON, of Liverpool, in the County of Lancaster, Engineer
and Boiler Maker, do hereby declare the nature of the said Invention for
"CERTAIN IMPROVEMENTS IN MARINE STEAM ENGINES," to be as follows:-
My improvements relate to heating the "feed water" for boilers,.and the
more effectually condensing the, waste steam in engines used for. marine.
purposes.
I accomplish my object by surrounding the whole or part of the "discharge-
steam pipe" with a casing or jacket, and through the annular passage thus
formed bringing the feed water for the boilers, or in passing the steam through.
the annular passage and using the "discharge steam-pipe" for the feed water-
supply.
Another modification of my Invention consists in constructing the waste-
steam pipe of a coiled, spiral, or other form giving length, and surrounding the
same with a casing or cylinder, leaving. sufficient space for the feed water
supply. The lengthy pipe could be used for the feed water and the space.
betwixt the pipe and outer casing for the waste steam..

page_text: •
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Francis Davidson in the Great Seal Patent Office on the
8th February 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
DAVIDSON, of Liverpool, in the County of Lancaster, Engineer and Boiler
Maker, send greeting..
.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of August; in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Francis Davidson, Her special licence that I, the said Francis Davidson;
my executors, administrators; and assigns, or such. others as I,. the said
Francis Davidson, my executors, administrators, and assigns; should at any
term agree with, and no others, from time to time and at all times there-
after during the time 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
IMPROVEMENTS IN MARINE STEAM ENGINES," upon the condition (amongst others)
that I, the said Francis Davidson, 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 Francis Davidson, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, 'to be particularly described and ascertained in and by the following
statement (that is to say):
:-
My improvements relate to heating the "feed water" for boilers, and
condensing the waste or "blown off" steam, or steam and surface water
together, when the said boilers are in connection with or form part of a motive-
power engine used for marine purposes.
I accomplish my object by surrounding the whole or part of the "discharge
steam" or "surface blow-off" pipe with a casing or jacket, and through the
annular passage thus formed bringing or forcing the "feed water" for the
boilers, or in passing the steam, or steam and surface water combined, through
the annular passage, and using the "discharge steam or surface blow-off"
pipe for the feed water supply.

page_text: steam
Another modification of my Invention consists in constructing the "waste
or "surface blow-off" pipe of a coiled, spiral, or other form, giving
length and surrounding the same with a casing or cylinder, leaving sufficient
space for the "feed water" supply. The coiled or spiral pipe could be used
for the "feed water," and the space between the said pipe and the outer casing
for the "waste steam" or steam and "surface water."
In marine steam engines as ordinarily constructed the "feed water" for the
boilers is taken from the "hot well" or from the ship's side, or part from both
sources, and the "waste steam" or "surface blow off" is carried from the
boilers to the ship's side. Now in the application of my Invention part or
whole of either of these pipes would be enclosed within a casing of the same
shape but of greater diameter, so that an annular passage would be formed,
and as the "feed water" and the "waste steam and surface blow-off" would
pass in opposite directions, the former would be raised in temperature before
reaching the boilers, thus effecting a saving in fuel, and the latter would be
condensed or considerably cooled before reaching the ship's side. In ships
where the "feed water" and "waste steam or "surface blow-off" pipes are
very short, a greater saving in fuel would be obtained by making the said pipes
and their casings of a coiled, spiral, or other winding form. In some cases
they could be partly coiled, spiral, or winding, and enclosed in a cylinder casing.
as above described.
Having now described the nature of my said Invention, and means
by which the same may be carried into practical effect, I would have it
distinctly understood that I do not confine myself to any detail in the carrying
out of my improvements, but what I claim as my Invention is, in steam ships
or vessels raising the temperature of the "feed water" for the boilers by the
heat in the "waste steam" or "surface blow-off" pipe, and condensing and
lowering the temperature of the said "waste steam" or "surface blow-off" by
the said "feed water."
In witness whereof, I, the said Francis Davidson, have hereunto set my
hand and scal, this Fourth day of February, in the year of our
Lord One thousand eight hundred and sixty-one.
Witness,
JOHN T. KING.
FRANCIS DAVIDSON. (L.S.)