IMPROVEMENTS IN THE MODE OF AND APPARATUS FOR OBTAINING MOTIVE POWER FROM STEAM AND OTHER ELASTIC FLUIDS
Year: 1864

page_text: LETTERS PATENT to David Clovis Knab, of No. 24, Rue de Dunkerque,
Paris, in the Empire of France, and 12, Abingdon Street, in the City
of Westminster, Civil Engineer, for the Invention of "IMPROVEMENTS IN
THE MODE OF AND APPARATUS FOR OBTAINING MOTIVE POWER FROM STEAM
AND OTHER ELASTIC FLUIDS."
Sealed the 7th March 1865, and dated the 12th September 1864.
PROVISIONAL SPECIFICATION left by the said David Clovis Knab at
the Office of the Commissioners of Patents, with his Petition, on
the 12th September 1864.
I, DAVID CLOVIS KNAB, of No. 24, Rue de Dunkerque, Paris, in the
Empire of France, and 12, Abingdon Street, in the City of Westminster,
Civil Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MODE OF AND APPARATUS FOR OBTAINING MOTIVE POWER
FROM STEAM AND OTHER ELASTIC FLUIDS," to be as follows :—
My Invention relates to a mode of obtaining motive power by the action of
steam or other elastic fluid on surfaces immersed, as hereafter described, in a
bath of liquid metal.
Figure 1 of the accompanying Drawing represents one form of engine by
means of which this principle may be carried into effect.
a, a, is a wheel or disc, mounted on the driving shaft b, and fitted at its
circumference with buckets c, c, serving as recipients to the motivo fluid;
d, d, is the metal to be liquified, contained in a case e, e, e, hermetically closed

page_text: by the cover ff. In the sides of this caso e, o, e, are set stuffing boxes,
through which pass the extremities of the driving shaft b. 9, furnace, by
which the metallic bath is heated to the required temperature; h, h, fluc, by
which the products of combustion are carried off after circulating round the
case e, e, e; i, pipe, by which the motive agent is carried to the bottom of the
metal bath; j, eduction pipe for the expended fluid.
In supposing, for example, that wo adopt steam as the working medium in
the engine above described, the bath d, d, may be composed of lead and tin,
or other suitable metals or alloys, which are reduced to and maintained in
fusion by the furnace g, the depth of the liquid mass being proportioned to
the amount of pressure required. The steam generated in a boiler mounted
apart in any desired position is led by the inlet pipo i from i' to m, and
acquires in its passage the samo temperature as that of the surrounding liquid
metal. On reaching the point m it passes into the recipients c of the disc a,
displacing the liquid metal contained therein, and so on successively from
recipient to recipient, till carried by the revolution of the wheel to the surface
of the bath, from whence it escapes by the eduction pipe j.
It may here be remarked that the liquid metal produces by its density the
.same effect as the mercurial column of tho barometer, and that the motive
fluid expands, as indicated by the Drawing, with mathematical regularity from
the moment of its introduction at the point m to its issue in h at the surfaco
of the bath.
From the preceding example it will be readily understood that the vapours
of ether, ammonia, methylène, sulphurous acid, and other highly volatilo
products may be substituted at will to that of water, the nature and tom-
perature of the metallic bath being modified accordingly. With motivo
agents of this class the bath may be composed of any casily fusible metal
(such, for instance, as the alloy of lead, tin, and bismuth, known as D'Arcet's
metal), and be maintained at a minimum temperature of 212° Fahrenheit,
the surplus heat being applied to superheat the fluid admitted at any desired
pressure, and thus increase the motive power by the whole amount of the
dilatation. The bath might even, if so desired, be composed of mercury,
although in engines of large dimensions the first expenso would be con-
siderablo.
Figure 2 represents a form of engine which may be used when heated air
is adopted as the motive medium. a, a, is the metal to bo liquified, contained
in a vessel b, b, the bottom of which forms a chamber above the furnace, as
seen in the Drawing; c, c, c, is a bell-shaped plunger of cast or wrought iron,
working vertically in the vessel b, b, and corresponding with the driving piston

page_text: of the ordinary steam engine; d, rod, passing through a collar e, e, set in the
brickwork f, f, and transmitting to the driving shaft the motion of the
plunger c; g, furnace; h, h, h, pipe, by which the air is admitted from a
pump placed in any suitable position; i, i, i, fluc, in which the products of
combustion circulate round the vessel b, b, on their way to the chimney
through the conduit j. The cold air forced in by the pump is first heated to
a certain extent in the portion of the pipe which passes through the
conduit ; and the corresponding portion of the flue i. From the lower bend
upwards this pipe is exposed to the direct action of. the fire, and the air thus
brought to the required temperature passes into the plunger c, c, through the
opening k. When tho up stroke of the plunger is completed, as seen in the
Figure, the air is exhausted by the action of the pump, and, is cooled on its
return by any suitable means; the plunger then descends to its starting point,
and so on alternately.
From the inspection of the Drawing it will be readily understood that all
leakage of the motive fluid is rendered impossible by the pressure of the
liquid metal, whatever may be the form of engine employed. It need scarcely
be observed that the arrangements above described are only given as examples
of the application of liquid metal baths, which forms the base of my Invention,
and that the general details of construction may be varied according to
circumstances.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Clovis Knab in the Great Seal Patent Office on
the 9th March 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
CLOVIS KNAB, of No. 24, Rue de Dunkerque, Paris, in the Empire of France,
and 12, Abingdon Street, in the City of Westminster, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of September, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said David Clovis Knab, Her special licence that I, the said David
Clovis Knab, my executors, administrators, and assigns, or such others as [,
the said David Clovis Knab, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times

page_text: 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 "Im-
PROVEMENTS IN THE MODE OF AND APPARATUS FOR OBTAINING MOTIVE POWER PROM
STEAM AND OTHER ELASTIC FLUIDS," upon the condition (amongst others) that I,
the said David Clovis Knab, my executors or administrators, by an instru-
ment in writing undor 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 Offico within six calendar months next and imme-
diately after the date of the said Lotters Patent.
NOW KNOW YE, that I, the said David Clovis Knab, do hereby declare
the nature of the said Invention, and in what manner' the same is to bo
performed, to be particularly described and ascertained in and by the fol-
lowing statement, referenco being had to the Figures of the accompanying
Drawing, and to the letters marked thereon, that is to say :-
My Invention relates to a mode of obtaining motive power, by the action of
steam or other elastic fluid on surfaces immersed, as hereafter described, in a
bath of liquid metal.
Figure 1 of the accompanying Drawing represents one form of engino by s
means of which this principle may be carried into effect.
a, a, is a wheel or disc, mounted on the driving shaft b, and fitted at its
circumference with buckets c, c, serving as recipients to the motive fluid;
d, d, is the metal to bo liquified, contained in a case a, e, e, hermetically closed
by the cover f. f. In the sides of this caso e, e, e, aro set stuffing boxes,
through which pass the extremities of the driving shaft b. g, furnace, by
which tho metallic bath is heated to the required temperature; h, h, flue, by
which the products of combustion are carried off after circulating round the
case e, c, c; i, pipe, by which the motive agent is carried to the bottom of the
metal bath; j, eduction pipe for the expended fluid.
In supposing, for example, that I adopt steam as the working medium in
the engine above described, the bath d, d, may be composed of lead and tin,
or other suitablo metals or alloys, which are roduced to and maintained in
fusion by the furnace g, the depth of the liquid mass being proportioned to
the amount of pressure required. The steam generated in a boiler mounted
apart in any desired position is led by the the inlet pipe i from i¹ to m, and
acquires in its passage the same temperature as that of the surrounding liquid
metal. On reaching the point in it passes into the recipients c of the disc a,
displacing the liquid metal contained therein, and so on successively from

page_text: recipient to recipient, till carried by the revolution of the wheel to the surface
of the bath, from whence it escapes by the eduction pipe j.
It may here be remarked that the liquid metal produces by its density the
same effect as the mercurial column of the barometer, and that the motive
fluid expands, as indicated by the Drawing, with mathematical regularity from
the moment of its introduction at the point m to its issue in n at the surface
of the bath.
From the preceding example it will be readily understood that the vapours
of ether, ammoniac, methylene, sulphurous acid, and other highly volatile
products may be substituted at will to that of water, the nature and tem-
perature of the metallic bath being modified accordingly. With motive
agents of this class the bath may be composed of any easily fusible metal
(such, for instance, as the alloy of lead, tin, and bismuth, known as D'Arcet's
metal), and be maintained at a minimum temperature of 212° Fahrenheit,
the surplus heat being applied to superheat the fluid admitted at any desired
pressure, and thus increase the motive power by the whole amount of tho
dilatation. The bath might even, if so desired, be composed of mercury,
although in engines of large dimensions the first expense would be con-
siderable.
Figure 2 represents a form of engine which may be used when heated air
is adopted as the motive medium. a, a, is the metal to bo liquified, contained
in a vessel b, b, the bottom of which forms a chamber above the furnace, as
seen in the Drawing; c, c, c, is a bell-shaped plunger of cast or wrought iron,
working vertically in the vessel b, b, and corresponding with the driving piston
of the ordinary steam engine; d, rod, passing through a collar e, e, set in the
brickwork ff, and transmitting to the driving shaft the motion of the
plunger c; g, furnace; h, h, h, pipe, by which the air is admitted from a
pump placed in any suitable position; i, i, i, flue, in which the products of
combustion circulate round the vessel b, b, on their way to the chimney
through the conduit j. The cold air forced in by the pump is first heated to
a certain extent in the portion of the pipe h which passes through the
conduit j and the corresponding portion of the flue i. From the lower bend
upwards this pipe is exposed to the direct action of the fire, and the air thus
brought to the required temperature passes into the plunger c, c, through the
opening k. When the up stroke of the plunger is completed, as seen in the
Figure, the air is exhausted by the action of the pump, and is cooled in its
return by any suitable means; the plunger then descends to its starting point,
and so on alternately.
From the inspection of the Drawing it will be readily understood that all

page_text: leakage of the motive fluid is rendered impossiblo by the pressure of tho
liquid metal, whatever may be the form of engine employed. It need scarcely
be observed that the arrangements above described are only given as examples
of the application of liquid metal baths, which forms the base of my Invention,
and that the general details of construction may be varied according to
circumstances.
Having now described the nature of my said Invention, and the manner of
carrying it into effect, I declaro that I claim and desire to secure by Letters
Patent the mode of obtaining motive power by the action of steam, or other
elastic fluid on surfaces immersed in a bath of liquid metal, in manner
substantially as abovo described and shown by tho Figures of the annexed
Drawing.
In witness whereof, I, the said David Clovis Knab, have hereto set
my hand and seal, this Eighth day of March, in the year of our Lord
Ono thousand eight hundred and sixty-five.