CERTAIN IMPROVEMENTS IN PRODUCING AND EMPLOYING STEAM AND THE GASEOUS PRODUCTS OF COMBUSTION FOR OBTAINING MOTIVE POWER
Year: 1856

page_text: LETTERS PATENT to Jean Baptiste Clara; of 39, Rue de' l'Echiquier, Paris,
in the Empire of France, and 4; South Street, Finsbury, London, Civil
Engineer, for the Invention of "CERTAIN IMPROVEMENTS IN PRODUCING AND
EMPLOYING STEAM AND THE GASEOUS PRODUCTS OF COMBUSTION FOR OBTAINING
MOTIVE POWER."
Sealed the 3rd February 1857, and dated the 13th August 1856.
PROVISIONAL SPECIFICATION left by the said Jean Baptiste Clara at
the Office of the Commissioners of, Patents, with his Petition, on the
13th August 1856.
I, JEAN BAPTISTE 'CLARA, of 39; "Rue de l'Echiquier, Paris, in 'the *Empire
of France, and 4, South Street, Finsbury, London, Civil Engineer, do hereby
declare the nature of my said Invention of "CERTAIN IMPROVEMENTS IN PRO-
DUCING AND EMPLOYING STEAM AND THE GASEOUS PRODUCTS OF COMBUSTION FOR
OBTAINING MOTIVE 'POWER," to be as follows, that is to say :-
These improvements relate, first, to the improved construction of boilers
for marine and other engines in which the furnace is rendered smoke-
consuming.

page_text: Secondly, to improved arrangements for economising the heat of the furnace,
thereby obtaining a more rapid generation of steam, and also for preventing
"priming" of the same..
Thirdly, to means for condensing the steam from soft water and employing
such condensed steam for feeding the boiler, thus rendering a fresh supply of
water unnecessary, and preventing the incrustation of the boiler.
Fourthly, to a mode of superheating the steam previous to its entering the
cylinders.
Fifthly, to the method of uniting and protecting the joints of the boiler and
fire box.
This improved boiler is similar to that employed in locomotives. The fire
box is formed with an inner casing of copper, which casing contains water; it
is fixed to the outer casing by stays or other means. Two hollow partitions
or chambers for containing water are fixed transversely to the side casing;
openings are made in these partitions for the passage of the gases and smoke
arising from the furnaces. There are two furnaces, separated by a hollow
partition containing water, and each furnace is formed with an arch or roof of
fire brick or fire clay, perforated with a number of small holes, through which
the smoke passes and becomes partially consumed when the fire clay is red
hot. The fire bars and doors are of the usual construction. The doors are
furnished with a register or air valve for admitting air into the furnace when
necessary, also with holes for examining the state of the fire. The combustion
of the gaseous products is further. completed by passing through an opening
made in the upper part of the first partition of the fire box, also through
another opening made in the lower part of the second partition, when they enter
a chamber furnished with a fire clay door previous to passing through the firo
tubes of the cylindrical boiler, fixed by angle iron and rivets, or by other means,
hereafter described, to the fire box. On the top of the tubular boiler is placed
a steam dome, in which is a steam pipe furnished with a regulator or valve
connected to a rod passing through the dome, which rod has a winch handle
for the purpose of turning the steam on or off. On the top of the dome is a
safety valve, the steam from which is made to pass into a reservoir of water.
Under the regulator and around the pipe is fixed a number of sheets of wire
gauze separated by rings; the gauze prevents the priming of the steam previous
to its entering the steam pipes. This pipe passes out of the dome along the
top of the fire box in the front part of which it enters. The steam from, this
pipe then passes through a number of small curved pipes placed on each side
of the middle partition in the fire box, the heat in which causes the steam
.

page_text: contained in the curved pipes to be superheated previously to its entering the
cylinders.
At the end of the tubular boiler is a smoke box or chamber, upon the top
of which the chimney is fixed, furnished with a damper or regulating slide for
regulating the draught. At the bottom of the smoke box enters two pipes
from the cylinder, the waste steam from which passes into a large tube secured
to the smoke box, the end of which tube is curved and dips in the soft water
contained in a reservoir placed under the tubular boiler. The steam and hot
air raises the water to a high temperature, and also produces a draught in the
furnace. This reservoir, from which the boiler is fed, consists of an oblong
vessel of sheet iron or copper provided with a cover; it is divided by a parti-
tion of wire gauze, which prevents the impurities, such as cinders, dust, ashes,
&c. conveyed by the before-mentioned tube from the smoke box into the water,
from passing to the other side of the partition, where the water is obtained
for feeding the boiler. On the top of the cover is a waste pipe furnished with
a spring valve, which pipe enters the upper part of the chimney, and is in.
connection with the air pump.
The condenser (which should be placed at the lower part of the ship) is
provided with a cover, through which one pipe enters to convey the steam, and
another to convey sea or other water; at the bottom also is fixed a tube for
the passage of cold water. A series of large tubes are fixed at their ends to
two chambers. In the interior of these large tubes small tubes are placed,
and passing through the chambers, the steam from the steam cylinder enter-
ing the chambers, & in the space between the two tubes, becomes condensed by
the cold water surrounding the large and within the small tubes. The con-
densed steam and air are pumped through a tube at the bottom of the
condenser by means of the air pump into a tube supplied with a valve, which
tube enters the cover of the hot water reservoir or cistern. In this manner
the water in the boiler is reemployed, and being soft, it prevents the incrusta-
tion of the boiler. The waste steam from the condenser passes through a
cylindrical vessel placed on the top of the hot water reservoir, and furnished
with a regulator; it contains a number of wire gauze plates for purifying
the steam from small particles of water previous to its egress through a tube
passing from the vessel, and connected to a number of small heating tubes
placed parallel with each other at the back of the fire box; the steam in the
tubes thereby becomes heated. To prevent the necessity for frequent repairs
of the fire box and boiler as now constructed I employ the following means:-
The part to be united should be moistened with a saturated solution of borax,

page_text: the rivets being dipped in the same solution. The joints of the interior parti-
tions and fire box are united together by moistening them with the borax
solution, and thon placing upon them small pieces of brass mixed, with
powdered borax, and which are melted so as to brâze or: solder the parts
together by means of a jet of gas applied by a blow pipe or .by. other.suitable
A strip of lead may also be soldered at the joints on the surfaces. in
contact with the water. The angles of the furnaces may also be covered with
powdered fire clay to protect the joints and the solder:.
To prevent leakage in the sheet iron casing: and boiler; all the parts to. be
united after the holes for the rivets are made should be tinned; I afterwards
solder the joints internally and externaly by means of thin strips of leal: If
it is necessary to reduce the length of the tubular boiler, a heating: cylinder
may be placed parallel on the side of it in connection with fire tubes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Jean Baptiste Clara in the Great Seal Patent Office on the
13th February 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JEAN
BAPTISTE CLARA, of 39, Rue de l'Echiquier, Paris, in the Empire of France,
and 4, South Street, Finsbury, London, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of August, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Hér heirs and successors, give and grant unto me, the said
Jean Baptiste Clara, Her special license that I, the said Jean Baptiste
Clara, my executors; administrators, and assigns, or such others as I, the
said Jean Baptiste Clara,. 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 "CERTAIN
IMPROVEMENTS IN PRODUCING AND EMPLOYING STEAM AND THE GASEOUS PRODUCTS
OF COMBUSTION FOR OBTAINING MOTIVE POWER," upon the condition (amongst
others) that I, the said Jean Baptiste Clara, by an instrument in writing
under my hand and seal, should particularly describe and ascertain the

page_text: nature of the said Invention, and in what manner the same was to be per-
formed, 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 Jean Baptiste Clara, 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 thereof, reference being had to the Drawings hereto
annexed, and to the figures and letters marked thereon, that is to say:-.
These improvements relate, first, to an improved construction of boilers for
marine and other low-pressure condensing engines in which the furnace is
rendered smoke-consuming.
Secondly, to improved arrangements for economising the heat of the furnace,
thereby obtaining a more rapid generation of steam, and also for preventing
"priming" of the same.
Thirdly, to the employment of soft water for feeding the boiler, and in
means for condensing the steamn thereof and reemploying the condensed
steam, whereby I prevent the incrustation of the boiler.
Fourthly, to a mode of superheating the steam previous to its entrance into
the cylinders.
Fifthly, to the method of uniting and protecting the joints of the boiler
and-fire.box.
Figure 1 of the accompanying Sheet of Drawings represents a section, and
Figure 2 an elevation, of the front of the fire boxes; Figure 8, a cross section
through A, B; Figure 4, a cross section through the line C, D; Figure 5, a
longitudinal section of the boiler, passing through the middle of the furnace
and boiler;. Figure 6, a cross section through EF; Figure 7, a sectional plan
of the fire boxes; Figure 8, plan of the hot-water reservoir; Figure 9 plan, and
Figure 10 an elevation of the condenser; Figures 11 and 12, a section of the
condensing tubes, full size. The boiler shewn is in some respects similar to
the present locomotive boilers; but the-arrangement of the furnace is different,
being better suited for the thorough combustion of the fuel; the heating
surfaces are also much greater.
. In order to render the description of the Invention more intelligible, I
bave divided it into two heads, which I entitle first and second action of the
caloric.
First Action of the Caloric.-The- fire boxes A, A, Figures 1, 2, 3, 4, 5,
and 7, are divided by, a partition A' filled with water; each furnace is

page_text: formed with an arched roof, made of refractory clay, of the kind employed
för gas retorts, and should be, if possible, in a single piece. The arched
roof rests on pieces of iron, which, to obviate the defects of expansion, are
laid loosely on brackets screwed to the sides of the fire box. Behind each
screw is soldered a copper washer to prevent the screw from passing through.
The extremities of the supports shewn in Figure 1, as also the sides of
the fire boxes, should be occasionally coated with a clay wash so as to
prevent oxidation. Instead of the means before described, the arched roof
may rest on clay supports fixed at the height of the grate. A part of the
furnace is moveable, and fixed by screws, Figure 2, to the front, the doors
being screwed to it. To enable the roofs to be placed in position this
portion of the front must be removed. The roofs are carefully secured
-with-bricks-and-clay. The roofs-are-perforated with small holes, and serve to
raise the temperature in the fire box, and at the same time permit of placing
on the grate a deep layer of fuel through which the air is caused to pass; a
part of the gases produced are then burned either in the furnace or in passing
through the small holes in the roof, by which means the gases are forced to
mix with the air after passing through the fuel. The combustion of the gases
is afterwards completed in the space or chamber B of the fire box in their
passage between the partitions B, C, filled with water, and before they arrive
at the tubes of the cylindrical part of the boiler. The object of the boiler
tubes is therefore to absorb the caloric produced, and their diameter should
not exceed two inches. These tubes last much longer than in the ordinary
systems, not being exposed to the direct action of the fire, and not liable to
incrustation; they may be fixed by screws, and passed through the smoke
box, as usual. The extremities of the tubes, which are previously strengthened
and formed with a screw, are screwed to the plate, the holes of which are
tapped to the same guage, so as to receive them. A mandril rather larger
than the hole in the tube is then passed through the smoke box by means of a
rod, and this mandril, after having joined the thread, falls into the fire box.
At the side of the smoke box the tubes are mounted in the ordinary way with
ferrules. The doors of the furnace, Figure 2, have a small sliding door or
disc to admit air to the fuel, as required; a sight-hole D, Figures 2 and 5,
allows the stoker to judge by the color of the flames the extent to which the
damper should be opened. A small quantity of air directed on the fuel in this
manner causes the immediate combustion of the gases. This operation may be
frequently repeated, as in this arrangement of furnace the thickness of the
layer of fuel may be about six inches; by this means the utilisation of fuel

page_text: On
is carried to its maximum point. The grates are formed of moveable bars,
every two of which are provided with a projecting piece, Figure 5, by which
they may be taken hold of and shaken to throw off the scorice. In the space
between the water partition C and the cylindrical portion of the boiler is a
door closed with bricks. In the usual construction of boilers, the repair of the
fire boxes and other parts of the boilers requires to be frequently performed,
owing to the alternate expansion and contraction of the metals by which
the rivets are loosened. I obviate these defects in the following manner:-
The inner fire box, which should be of copper, is rivetted in the ordinary
manner, leaving, if required, a greater distance than usual between the rivets,
the edges of the joints being left rough. Before rivetting the parts together,
the rivets and the parts to be united should be washed with water saturated
with borax. Each portion of the fire box should be set up at such a height
as to permit of a person passing under it to operate in the part desired.
the interior of the fire box I place on the joints (previously washed with a
solution of borax) small pieces of brass sprinkled with powdered borax, which
is heated by a small fire box underneath, and I fuse the brass by a jet of
lighted gas from a gas blow pipe. The fused brass runs into the parts covered
with the borax, the rivets also being soldered by this process. The whole of
the joints are thus soldered in portions of two to three inches at a time. To
give more strength to the surface in contact with the water, a thin strip of
lead should be soldered at the joints; the strip expands and contracts without
breaking, and resists the action of the water. The angles of the furnace are
further secured by bricks moulded on purpose to protect the joints and soldered
parts; for these may be substituted clay supports, which have the advantage
of increasing the temperature. These supports are made in several pieces, in
order to facilitate the repair in case of damage. In order to obviate the leak-
age from the iron casings and cylindrical part of the boiler, I proceed as
follows: All the parts which are to be united are tinned after the piercing of
the rivet holes; they are then joined as usual, their edges being left rough,
and thin strips of lead are then soldered on the joints inside and outside, in
the manner above described. For a ship requiring a small sized boiler, a
single furnace may be employed, care being taken to place in the middle of
the partition B a tube of about the same diameter as the thickness of that
part. This tube communicates with the top of the fire box, so as to permit
the water to circulate freely. Without this precaution the top of this part
would burn, as the two lateral pressures, being equal, the circulation would be
effected with difficulty, and steam would be formed, which would remain a long

page_text: time above before escaping. This being the case, the portion exposed to the
inflamed gases would not long resist their action. The bottom of the par-
tition is formed, as shewn in Figure 3, to prevent the accumulation of deposits
from the water; this part may be made in the forin of an arch a, Figure 3,
without the middle tube. The partitions B, C, and the fire boxes should be
furnished with tie pieces or bolts. The gaseous products of combustion, after
passing through the tubes of the cylindrical part of the boiler, enter at an
elevated temperature into the smoke box, Figure 5, being drawn by the steam
egressing from the cylinder, which steam is conducted by small pipes E into
the large tube F dipping into the reservoir G. The condensation of the steam
forms a vacuum in this tube, produces the draught as in locomotives, and
carries with it all the gaseous products of combustion. The tube F is slightly
immersed in the reservoir G, and the water it contains, after being heated by
the hot air and steam partly condensed-in -it,-serves to feed the boiler. The
smoke box is surmounted by a case forming a base for the chimney, which is
of a smaller diameter than those usually employed in ships. This case contains
a register composed of a plate sliding in a groove, and the register should be
so adjusted as to close perfectly. On getting up steam, or when stationary
this register is opened, and the combustion then commences as usual. When
at work the register is closed, and the draught is then caused by the steam.
On the top of the boiler is fixed a steam dome containing a valve or steam
regulator, and the pipe which conducts the steam to the cylinder, in the manner
hereafter described. The fan-shaped valve or regulator is secured by a cross
piece, which fixes it to a circular box, which is also adapted to the tube con-
ducting the steam to the cylinder. A number of sheets of metallic gauze
separated by flat rings, being supported either by the regulator box, by the
tube, or by the rings and screws, are fixed in the dome, and the steam is
forced before entering the regulator to pass through the wire gauze which
retains the small globules of water or "priming" with which it may be
charged. The steam, notwithstanding this operation, still contains small
particles of water; which it is necessary to vaporize, so as to increase the
power of the steam. For this purpose, before entering the cylinders, the
'steam enters the fire boxes through the boxes H, H', united together by curved
tubes: These boxes are not fixed to the fire box, as the latter might be injured
by the expansion of the tubes; they are simply held in the fire box in the
place purposely made by means of wedges, the interstices being filled with
clay. These tubes should be placed a little higher than the position shewn
in the Drawing, to remove them as far as possible from the currents of

page_text: inflamed gases. The top of the steam dome is provided with a spring valve,
and its escape tube should pass into the reservoir, into which it conducts the
waste steam. The top is traversed by the axis of the regulator, and this axis
is worked. on deck by the hand.
Second. Action of the Caloric.-In order to employ the same water during
the whole voyage of the ship, and avoid incrustation, the condensation of
the steam is effected by bringing it in. contact with large cooling surfaces.
The condenser, Figures 9 and 10, is placed in the lower part of the ship;
it is composed of a case or cylinder having at its opposite sides one or
more pipes communicating with the sea. The water enters this case or
cylinder by the lower pipe A, circulates and egresses by the upper tube. B.
This case should contain a large number of concentric tubes, the arrange-
ment of which is represented on a larger scale, Figures 11 and 12. The
water covers the exterior of the large tube and the interior of the small one;
the annular space between the two receives the steam and air which are
drawn in by the air pump. The steam and air proceeding from the cylinder
enter the condenser through the tube C, and the air and condensed water
egress through the tube D in communication with the air pump; this
case or cylinder presents within a small compass a large condensing surface.
The air drawn in by the pump is forced by it into a pipe, which conveys
it into the chimney above the register. The water of condensation is forced
by the pump into the reservoir.G by means of a small pipe and valve E,
Figure 8. The double-acting air pump should be placed near the steam
cylinder. The water on coming from the condenser passes with the air
into a small cistern, whence it is drawn by a small pump into the large
reservoir G, the air then passing to the chimney; the air being, however, more
or less charged. with watery vapour, gives rise to a loss of water, which I
replace by distilled sea water. The distilling apparatus consists of four or
more tubes which pass through the fire box chamber. On one side these tubes
have an air-tight. door, which permits of their being cleaned, and on the other
side they pass to a box, supporting a small cylinder, placed vertically, and
terminated by a hemispherical cap; the box is provided at its lower part with
an escape tube and stop-cock. The sea water is passed into this boiler by a
small pump, and the steam produced is conducted at will by two small tubes,
each provided with a stop-cock either in the cistern or reservoir G, where the
indications of the level shew that it contains a sufficiency of water. The steam,
which in the latter case reaches the reservoir G, increases to some extent the
power of the second action of the caloric.

page_text: Figures 1, 4, and 5 represent four steam chests H, H', for heating the
steam of the first action. The three other boxes K, K', which perform the
same duty, are for the steam proceeding from the second action. The reservoir,
Figures 5, 6, and 8, is provided with a vertical cylinder L, in which are fixed
plates of wire gauze for preventing "priming," and with a regulator, the axis
of which extends to the deck. The two regulators may be worked by one
person on the deck of the vessel. In the reservoir is a partition M, of which
one portion is composed of metallic gauze to stop any particles of ashes and
dust which otherwise might pass into the feeding part; at the upper part of
this partition is an opening to give passage to the steam and heated air.
Various other means for assuring the purity of the feed water may be em-
ployed. The reservoir is furnished with a valve in the tube which passes to
the chimney; this valve is pressed by a spring, and is so adjusted that the
tension in the cistern may be about two hundred and twelve degrees Fahrenheit.
It is, however, requisite that this spring should be capable of pressing to a
greater extent to compensate for an occasional increase of draught. To provide
for this contingency, the valve should be loaded, and the expansion of the
steam, by the second action, be adjusted so that the consumption of steam may
be less than that in the first action. By this means the tension of the steam is
increased in the reservoir; the resistance to the steam producing the draught
is also increased, while the action of the draught is diminished. Should the
cylindrical part of the boiler be two long, it may be reduced; but in order to
have a sufficient heating surface in the tubes, the heated air should be brought
back in another cylindrical body parallel to the first, as represented at Figure 4.
The chimney in this caso would be placed on the body, and in front of the
boiler.
Having thus described the nature of my said Invention, and the manner in
which the same may be carried into execution, I would have it understood
that I do not restrict myself to the precise details herein laid down, so long
as the peculiar features of my Invention be retained; but what I claim is,-
First, the general arrangement and construction of marine and other low-
.pressure condensing engines in which soft water is used for the generation of
steam, and reemploying it during the voyage, thereby economising fuel and
.preventing incrustation of the boiler, as herein-before described, and referred to
in the Figures of the annexed Drawing.
Secondly, the method of constructing boiler furnaces, as herein-before
described, and referred to in Figures 1, 2, 3, 4, 5, 6, 7, and 8 of the
Drawings

page_text: Thirdly, the improved arrangements for obtaining a larger heating surface in
steam boilers than at present, and for employing the waste steam and hot air
to heat the feed water, as herein-before described, and represented in the
accompanying Drawing.
Fourthly, the improved construction of condensing apparatus, as herein-
before described, and referred to in Figures 9, 10, 11, and 12, of the annexed
Drawing.
Fifthly, the method of superheating the steam previously to its entrance
into the cylinders, as herein-before described, and shewn in Figures 1, 4, and 5
of the Drawing.
Sixthly, the method of securing the edges of the fire box and boiler, as
herein-before described.
. In witness whereof, I, the said Jean Baptiste Clara, have hereunto set
my hand and seal, this Ninth day of February, in the year of our
Lord One thousand eight hundred and fifty-seven.
JN BAPT CLARA. (L.S.)