IMPROVEMENTS IN CONDENSING STEAM IN ENGINES WHERE SUPERHEATED " STEAM IS USED
Year: 1859

page_text: LETTERS PATENT to Thomas Howard, of King and Queen Iron Works,
Rotherhithe, in the County of Surrey, Engineer, for the Invention of
"IMPROVEMENTS IN CONDENSING STEAM IN ENGINES WHERE SUPERHEATED
"
STEAM IS USED."
Sealed the 20th December 1859, and dated the 25th June 1859.
PROVISIONAL SPECIFICATION left by the said Thomas Howard at the
Office of the Commissioners of Patents, with his Petition, on the
25th June 1859.
I, THOMAS HOWARD, of King and Queen Iron Works, Rotherhithe, in the
County of Surrey, Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN CONDENSING STEAM IN ENGINES WHERE SUPERHEATED
STEAM IS USED," to be as follows:-
My Invention consists in condensing the steam generated in boilers, which
have attached to or combined with them or with the cylinders or other
parts of the engine, any apparatus or means for superheating the dense steam
generated in the boilers, I admit such steam after having done its duty into a
vessel to be condensed, and instead of bringing it in contact with sea or other
external water, I circulate the water of injection through suitable spaces
exposed to external cold water, and bring the steam into contact therewith,
whereby the same water or nearly so, may be continually returned to the

page_text: boilers. This system of condensation was invented by me, and is the subject
of former Letters Patent, therefore I only intend to claim its adaptation as
aforesaid.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Howard in the Great Seal Patent Office on the
24th December 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, T, THOMAS
HOWARD, of the King and Queen Iron Works, Rotherhithe, in the County of
Surrey, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of June, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Howard, Her special licence that I, the said Thomas Howard, my
executors, administrators, and assigns, or such others as I, the said Thomas
Howard, 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 "IMPROVEMENTS IN CON-
DENSING STEAM IN ENGINES WHERE SUPERHEATED STEAM IS USED," upon the con-
dition (amongst others) that I, the said Thomas Howard, 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 Thomas Howard, 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 thereof, that is to say :-
My Improvements consist in condensing, as herein-after described, steam
which is generated in boilers having attached to or combined with them or
with the cylinders or other parts or adjuncts of steam engines any apparatus
or means for superheating the dense steam.
I admit such superheated steam after having done its duty in the cylinder

page_text: or otherwise, into a vessel to be condensed, such as is commonly termed a
condenser. but instead of subjecting it to the contact of external cold water
injected thereinto from the sea or other source containing salts or impurities,
I subject it to the contact of the same water repeatedly, which is cooled
by circulating it, together with that resulting from the condensed steam,
through metallic tubes, vessels, or channels having their opposite surfaces
presented in any suitable manner or in any convenient position to a current of
the external cold water, and which when the supply is limited should pass in
an opposite direction to the water within. The circulation of this condensing
water is effected by withdrawing it by the ordinary air-pump into the hot
cistern and passing it thence by the atmospheric pressure, through the cooling
channels again into the condenser, where it is injected amidst the steam con-
tinuously, or it may be intermittently by actuating a valve or injection cock
accordingly. It may also be cooled by passing cold water through tubes or
channels set in a hot cistern arranged for such purpose. The boilers will
now be fed by the ordinary means, with the circulating water constantly
replenished by that resulting from the condensation of the steam. The
injection is regulated as in the ordinary method, which method may be
retained in case of derangement of the cooling apparatus, or used so far as
will supply the waste in the boilers. Or, stills may be employed to furnish
pure water for this purpose; but I prefer to admit the needed small quantity
of external water, and eject a little water from the boiler periodically, from
which will result only a small deposit of insoluble matters therein, requiring
removal at distant intervals. Instead of employing the ordinary air-pump, as
before mentioned, I sometimes prefer to use a separate small pump or pumps
of only sufficient capacity to withdraw the warm water into the hot cistern,
and employ an air pump adequate only to the exhaustion of the air entering
by leakages (and none will now enter in combination with the injection water),
thus relieving the machinery of the engine from the considerable and sudden
strain of the ordinary combined air and water pump. Or the water may be
circulated without bringing it into contact with the atmosphere, when the hot
cistern may be dispensed with, and a loaded valve should then be fitted at the
point of injection in place of the injection cock to insure the fullness and also
the safety of the cooling apparatus. Oil and not tallow should be used for
internal lubrication, and removed or ejected from the hot cistern occasionally;
and the cooling channels should be suitably arranged for cleaning and a
perforated screen be placed over the inlet of the circulating-apparatus.
The external cooling water can be supplied from any suitable source, and
may be, by means of pumps or other motors, actuated by the engine or other-

page_text: wise, and also may be in marine engines by the transmission or passago and
impact of the water effected by the motion of the vessel, or by the action of
the propelling instruments. Or the combined air and water pump, the
ordinary function of which will now be diminished, can be fitted with a solid
piston, disc or plunger, and by a proper arrangement of the respective
valves, be made to perform the additional duty of circulating the cooling
water.
By means of my present improvements the extent of cooling surface
required, and other accessories will be greatly reduced below that heretofore
employed, and rendered more economically and practically available.
Now, whereas the system of condensation by the re-injection of the same
water was invented by me, and is the subject of former Letters Patent, I only
hereby claim its adaptation and combination with boilers or tubular or cellular
generators as aforesaid, or in conjunction with any of the appliances mentioned,
the same being particularly applicable when in such combination, the super-
heated steam is worked more expansively than is generally practised with
dense steam, particularly in navigation.
In witness whercof, I, the said Thomas Howard, have hereunto set
my hand and seal, this Twenty-third day of December, One thousand
eight hundred and fifty-nine.
THOMAS HOWARD. (L.S.)