IMPROVEMENTS IN STEAM BOILERS OR GENERATORS, AND IN THEIR FURNACES
Year: 1875

page_text: LETTERS PATENT to Marie Léon Burct de Longagne, of Brussels, in
the Kingdom of Belgium, Civil Engineer, for the Invention of
⚫ IMPROVEMENTS IN STEAM BOILERS OR GENERATORS, AND IN THEIR FURNACES."
Scaled the 4th June 1875, and dated the 10th April 1875.
PROVISIONAL SPECIFICATION left by the said Maric Léon Burct
-
de Longagne at the Office of the Commissioners of Patents, with
his Petition, on the 10th April 1875.
I, MARIE LÉON BURET DE LONGAGNE, of Brussels, in the Kingdom of
Belgium, Civil Engineer, do hereby declare the nature of the said
Invention for IMPROVEMENTS IN STEAM BOILERS OR GENERATORS, AND IN
THEIR FURNACES," to be as follows.-
-
My Invention consists inter alia of a novel construction and arrange-
ment of steam boilers in which the fire in the fire-place acts directly
upon a series of horizontal or slightly inclined water tubes projecting
from a vertical chamber or case through which the water to be evaporated
1s fed into the said tubes, and the steam generated rises and passes into
'

page_text: one or more drying chambers and superheaters previous to its passing
out of the boiler for use.
The said vertical chamber or chest, hercin-after called the body of the
boiler, is by preference of rectangular section, and is mounted above the
fire-place at the front part thereof To the back of the said body of
the boiler are affixed the tubes aforesaid, which incline slightly down-
ward and extend to near the back wall of the boiler, and arc by
preference supported by a vertical plate so as to give free action to the
expansion or contraction of the said tubes. The said tubes open at onc
end into the body of the boiler, and are closed at their other or rear
ends, thus forming a series of water spaces projecting from the back of
the body of the boiler directly over the fire-places. The body of the
boiler is divided into two compartments communicating one the with
other at top and bottom by a vertical partition parallel with the face-of
the boiler and extending above and below the lines of tubes. Each of
the said tubes is divided into two compartments by a longitudinal plate
or partition suitably supported and extending from the fore end of the
said tube to near its rear end, where the two compartments communicate
one with the other. To the front end of cach of the said lower com-
partments of the tubes is affixed an enlarged or funnel-shaped mouthpiece
which passes through the rear compartment and partition of the body of
the boiler and opens into the front compartment, being affixed at its
upper part to the partition herein-before described, and at its lower end
extending as far as the front plate of the body of the boiler. The lower
compartments of the tubes thus communicate with and open directly
into the front compartment of the body of the boiler whilst the upper
compartments of the said tubes open into and communicate directly
with the rear compartment of the said body of the boiler.
In the front plate of the body of the boiler are made suitable holes or
apertures opposite the mouth of each of the tubes for the purpose of
gaining access to and cleansing the said tubes when required. The said
holes or apertures are closed by metal plugs or caps, which may be
screwed into the said holes or apertures or otherwise affixed thereto.
The upper part of the body of the boiler receives the steam which
rises from the water The steam is then in a highly saturated state and
requires to be dried, and may be superheated before being used. For
purpose a cylindrical steam chest is affixed to the body of the boiler
this

page_text: so as to project therefrom above the tubes and to receive and dry the
steam generated in the boiler previous to such steam being used. The
said steam chest is composed of two cylinders or tubular cases of different
diameters, one within the other, and closed at their rear ends by a
suitable cap or covering plate. In the annular space between the two
cylinders is fixed a helix so as to form with the sides of the cylinders a
helical channel or passage for the steam. At the rear end of the said
steam chest the outer case or cylinder communicates with the inner
space or cylinder by apertures formed in the latter. The steam from the
upper part of the body of the boiler passes through suitable apertures or
through a suitable pipe into the annular space around the inner steam
chest, and following the helical channel or passage aforesaid is brought
well into contact with the heated outer cylinder and is dried thereby.
It then enters the cylinder from which it passes off for use through
a suitable steam pipe. Or the steam from the body of the boiler may
first pass into the central or inner cylinder or chamber of the said steam
chest and then pass out through the helical passage in the annular space
formed between the two cases. One or more steam chests constructed
as herein-before described, or if preferred composed of a single cylinder
in which a helical blade round a shaft forms the spiral steam passago
may be used with my improved boilers, and when it is required to
superheat the steam a superheater of similar construction to the steam
chests herein-before described may be used, the steam then passing from
the steam abest on chests into the sunorhantor and thence to the storm

page_text: Any suitable description of furnace may be used for heating my
improved boilers, but I prefer to apply thereto the improved smoke-con-
suming furnace herein-after described. The said smoke-consuming
furnace consists of two fire-grates, the first or upper grate inclining
slightly downwards from the furnace door and extending from just 5
below the furnace door to about one-third of the length of the furnace
The second or lower grate extends from the back of the furnace to
within a sbort distance of the front, and is inclined downward towards
the front so as to pass under the upper grate, and a passage is thus
left for air to enter between the two grates. A flue is formed in the 1
side and back walls of the said furnace and opens into the furnace by a
suitable aperture in the said back wall underneath the lower grate
this means the air for the combustion of the fuel which enters the side
flues by apertures (furnished-with adjustable-valves or dampers) in the
front wall of the furnace passes along the flues in the side walls,
absorbing heat from the heated brickwork, and by the opening in the
back wall enters the furnace below the grates and passes between the
grate bars and between the upper and lower grates into the fuel on
the said grates.
By
The fuel is fed on to the upper grate by means of a hopper outside the
furnace door or by any other suitable contrivance. From the said upper
grate the fuel when in an incandescent state is pushed down on to the
second or lower grate where it continues to burn, consuming the smoke
emitted by the fuel freshly fed on to the upper grate, the smoke consump-
tion being further promoted by the air passing between the said grates
The ash-pit or space below the fire-grates is closed in front by a suitable
door which may be opened when a greater supply of air is required than
is furnished by the flues herein-before described. The chunney is, by
preference, situated in the roof of the boiler, which is provided with a
damper composed of several wings or shutters or louvres jointed to
a suitable frame and capable of motion round their axes By means of a
suitable lever or other mechanical arrangement the said shutters or
wings are opened or closed as required.
The boiler herein-before described having been filled with water to a
proper level, that is to say, to about four inches above the upper line
of tubes, the action produced by the heat of thic furnace will be as
follows: A general current or circulation of the water will soon take

page_text: place, the heat acting on the lower surface of the tubes will cause the
water in the lower portion of the said tubes to flow forward and pass
through the mouth-pieces of the said lower compartments into the front
compartment of the body of the boiler, and the cooler portion of the
water will pass from the back compartment of the body of the boiler
into the upper portions of the said tubes, thence round the partitions
in the tubes into the lower portions thereof, and thence into the front
compartment of the body of the boiler, and the said currents of water
will be more rapid as the heat becomes greater. The steam formed in
the said tubes and body of the boiler will follow the same course as the
water, and will rise with the water in the front compartment of the body
of the boiler and escape into the steam space above the water, and
will then pass in a highly saturated state into the steam chamber or
chambers hercin-after described, where it will be dried previous to
passing out of the boiler for use, or into the superheater, if a superhcated
is used.
The tubes used in connection with my improved boilers may be of the
character heroin-before described, that is to say, closed at their outer ends,
and divided longitudinally by horizontal or vertical partitions into two
compartments communicating one with the other; or the tubes may be
made double, that is to say, composed of an outer tube affixed to the
tube plate of the body of the boiler, and closed at its outer end, and an
inner tube affixed by its fore end to the partition in the body of the
boiler, and opening into the front compartment thereof, the said inner
tube extending to within a short distance of the closed end of the outer
tube. Or the said tubes may be bent into a syphon or U-shape, one
leg of cach of the said tubes being longer than the other, and extending
by a suitable mouth-piece into the front compartment of the body of the
boiler, into which compartment the said leg opens, the end of the other
leg being affixed to the tube plate, and opening into the rear com-
partment of the body of the boiler. Or the tubes may be set in series
of two tubes, one above the other, arranged and communicating one
with the other, as herein-after described, that is to say, a lower row or
series of tubes in which steam is to be generated is composed of tubes
divided into two horizontal compartments, and provided with mouth-
pieces, and in all respects similar to the tubes herein-before first
described An upper row of tubes is composed of similar tubes un-
provided with mouth-pieces, and affixed by their ends to the tube plate.

page_text: The tubes of the said two rows of Lubes communicate with each other
by pairs, that is to say, each tube of the upper row is in communication
with the tube immediately below it, a small chamber being formed for
the purpose in the inner compartment of the body of the boiler by means
of horizontal partitions.
The lower part of the body of the boiler is similar in all respects to
that herem-before described, but just above the lowest row of the under
tubes herein-before referred to, it is divided horizontally throughout its
whole length by a partition affixed to the tube plate, and the vertical
partition in the body of the boiler. The tubes of the lower row of the
series being thus no longer in direct communication with those of the
upper row, they are made to communicate the one with the other by a
series of holes or apertures made above cach tube in the vertical partition
of the body of the boiler.
The steam rising in the inner compartment of the body of the boiler
escapes through the said holes or apertures, and passes into the front
compartment of the said body of the boiler, where the water passing
with the steam mixes with the feed water, whilst the steam tends to rise
to the top of the body of the boiler; but as it is important that the
steam should be dried by passing through the upper tubes of each scries
its ascending motion is arrested by a metal horizontal partition, forming
an extension of the metal plate or partition in the said upper tube. The
steam by this means, after having traversed the vertical partition in the
body of the boiler, enters the lower compartment of the upper tube,
passes to the end of the said tube and returns through its upper com-
partment, it then enters the body of the boiler where its course is agai
arrested by a partition above the next row of under tubes, which
partition causes it to follow a similar course with respect to the series
of tubes above it as it did with respect to the lower series it has just
left. In like manner it traverses cach series of tubes till it has reached
the top of the body of the boiler from which it passes to the steam chests
or superheaters

page_text: filed by the said Marie Léon Buret de Longagne in the Great Seal
Patent Office on the 8th October 1875
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARIE
LÉON BURET DE LONGAGNE, of Brussels, in the Kingdom of Belgium,
Civil Engincor, sond greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of April, in the year of
our Lord One thousand eight hundred and seventy-five, in the Thirty-
cighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Maric Léon Buret de Longagne, Her
special license that I, the said Maric Léon Buret de Longagne, my
executors, administrators, and assigns, or such others as I, the said
Marie Léon Buret de Longagne, 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, excrcise, and vend, within the
United Kingdom of Great Britain and Ircland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN STEAM BOILERS OR
GENERATORS, AND IN THEIR FURNACES," upon the condition (amongst others)
that I, the said Maric Léon Burct de Longagne, my executors or
administrators, by an instrument in writing under my, or their, or one
of their hands and scals, 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 Scal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Maric Léon Buret de Longagne, do
hereby declare the nature of the 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, that is to say
My Invention consists in inter alia of a novel construction and
arrangement of steam boilers in which the fire in the fire-place acts
directly upon a series of horizontal or slightly inclined water tubes
projecting from a vertical chamber or case through which the water to

page_text: be evaporated is fed into the said tubes, and the steam generated rises
and passes into one or more drying chambers and superheaters previous
to its passing out of the boiler for use
The said vertical chamber or chest herein-after called the body of the
boiler is, by preference, of rectangular section, and is mounted above the t
fire-place at the front part thereof. To the back of the said body of
the boiler are affixed the tubes aforesaid, which incline slightly down-
wards and extend to near the back wall of the boiler, and are, by
preference, supported by a vertical plate so as to give free action to the
expansion or contraction of the said tubes The said tubes open at one 1
end into the body of the boiler and are closed at their other or rear ends,
thus forming a series of water spaces projecting from the back of the
body of the boiler directly over the fire-places. The body of the boiler
is divided into two compartments, communicating one with the other at
top and bottom, by a vertical partition parallel with the face of the 1
boiler, and extending above and below the lines of tubes. Each of the
said tubes is divided into two compartments by a longitudinal plate or
partition suitably supported and extending from the fore end of the said
tube to near its rear end where the two compartments communicate one
with the other. To the front end of each of the said lower compart- 2
ments of the tubes is affixed an enlarged or funnel-shaped mouth-piece
which passes through the rear compartment and partition of the body of
the boiler, and opens into the front compartment being affixed at its
upper part to the partition herein-before described, and at its lower end
extending as far as the front plate of the body of the boiler. The lower 2
compartments of the tubes thus communicate with and open directly
into the front compartment of the body of the boiler, whilst the upper
compartments of the said tubes open into and communicate directly
with the rear compartment of the said body of the boiler.
'
In the front plate of the body of the boiler are made suitable holes or 3
apertures opposite the mouth of each of the tubes for the purpose of
gaming access to and cleansing the said tubes when required. The
said holes or apertures are closed by metal plugs or caps which
may be screwed into the said holes or apertures, or otherwise affixed
thereto.
The unner part of the body of the boiler receives the steam which
3

page_text: requires to be dried and may be superheated before being used. For this
purpose a cylindrical steam chest is affixed to the body of the boiler so
as to project therefrom above the tubes, and to receive and dry the steam
generated in the boiler previous to such steam being used. The said
steam clost is composed of two cylinders or tubular cases of different
diameters, one within the other, and closed at their rear ends by a suitablo
cap or covering plate. In the annular space between the two cylinders
is fixed a helix so as to form with the sides of the cylinders a helical
channel or passage for the steam. At the rear end of the said steam
chest the outer case or cylinder communicates with the inner space or
cylinder by apertures formed in the latter. The steam from the upper
part of the body of the boilor passes through suitable apertures or
through a suitable pipe into the annular space around the inner steam
chest, and following the helical channel or passage aforesaid is brought
well into contact with the heated outer cylinder and is dried thereby, it
then enters the inner cylinder from which it passes off for use through a
suitable steam pipe. Or the steam from the body of the boiler may
first pass into the central or inner cyhnder or chamber of the said steam
chest, and then pass out through the helical passages in the annular
spacc formed between the two cases One or more steam chests con-
structed as herein-before described, or if preferred, composed of a single
cylinder, in which a helical blade round a shaft forms the spiral steam
passage may be used with my improved boilers, and when it is required
to superheat the steam a superheater of similar construction to the steam
chests herein-before described may be used, the steam then passing from
the steam chest or chests into the superheater, and thence to the steam
pipo for use.
For stationary boilers the side and back walls of the boiler are made
of brickwork and enclose the tubes and steam chests aforesaid, and
join the body of the boiler which may form the front wall e. In the
case of portable marine or locomotive boilers the said walls arc by
preference made of a double casing of sheet metal, the inner space
between the metal plates being filled with coke dust or other non-
conducting material. The walls of the furnace are formed of brickwork
for stationary and portable or locomotive boilers, and in the case of
marine boilers the walls and bottom of the furnace and ash pan are by
preference made of a double casing of sheet metal forming water spaces
connected with the body of the boiler herein-before described. The roof

page_text: The boiler herein-before described having been filled with water to a
proper level (that is to say) to about four inches above the upper line
of tubes the action produced by the heat of the furnace will be as
follows A general current or circulation of the water will soon take
place, the heat acting on the lower surface of the tubes will cause the
water in the lower portion of the said tubes to flow forward and pass
through the mouth-pieces of the said lower compartments into the front
compartment of the body of the boiler, and the cooler portion of the
water will pass from the back compartment of the body of the boiler
into the upper portions of the said tubes, thence round the partitions in
the tubes into the lower portions thereof, and thence into the front
compartment of the body of the boiler, and the said currents of water
will be more rapid as the heat becomes greater The steam formed in
the said tubes and body of the boiler will follow the same course as the
water, and will rise with the water in the front compartment of the body
of the boiler, and escape into the steam space above the water, and will
then pass in a highly saturated state into the steam chamber or
chambers herein-after described, where it will be dried previous to
passing out of the boiler for use, or into the superheater if a superheater
is used.
The tubes used in connection with my improved boilers may be of the
character hercin-before described (that is to say) closed at their outer
ends, and divided longitudinally by horizontal or vertical partitions into
two compartments communicating one with the other; or the tubes may
be made double (that is to say) composed of an outer tube affixed to the
tube plate of the body of the boiler and closed at its outer end, and an
inner tube affixed by its fore end to the partition in the body of the
boiler and opening into the front compartment thereof, the said inner
tube extending to within a short distance of the closed end of the outer
tube. Or the said tubes may be bent into a syphon or U shape, one leg
of each of the said tubes being longer than the other, and extending by
a suitable mouth-picce into the front compartment of the body of the
boiler, into which compartment the said leg opens, the end of the other
leg being affixed to the tube plate and opening into the rear compart-
ment of the body of the boiler. Or the tubes may be set in serics of two
tubes, one above the other, arranged and communicating one with the
other, as herein-after described (that is to say) a lower row or series of
tubes in which steam is to be generated is composed of tubes divided

page_text: into two horizontal compartments and provided with mouth-pieces, and
in all respects similar to the tubes herein-before first described, an
upper row of tubes is composed of similar tubes unprovided with mouth-
pieces, and affixed by their ends to the tube plate. The tubes of the
said two rows of tubes communicate with each other by pairs (that is to 5
say) cach tube of the upper row is in communication with the tube
immediately below it, a small chamber being formed for the purpose
in
the inner compartment of the body of the boiler by means of horizontal
partitions.
The lower part of the body of the boiler is similar in all respects to 1
that herein-beforo described, but just above the lowest row of the under
tubes herein-before referred to it is divided horizontally throughout its
wholo-length by a partition affixed to the tube plate and the vertical
partition in the body of the boiler. The tubes of the lower row of the
scries being thus no longer in direct communication with those of the 1
upper row, they are made to communicate the one with the other by a
series of holes or apertures made above each tube in the vertical partition
of the body of the boiler.
The steam rising in the inner compartment of the body of the boiler
escapes through the said holes or apertures and passes into the front 2
compartment of the said body of the boiler, where the water passing
with the steam mixes with the feed water, whilst the steam tends to riso
to the top of the body of the boiler. But as it is important that tho
steam should be dried by passing through the upper tubes of each series
its ascending motion is arrested by a metal horizontal partition forming 2
an extension of the metal plate or partition in the said upper tube. The
steam by this means, after having traversed the vertical partition in the
body of the boiler, enters the lower compartment of the upper tube,
passes to the end of the said tube, and returns through its upper com-
partment It then enters the body of the boiler, where its course is 3
again arrested by a partition above the next row of under tubes, which
partition causes it to follow a similar course with respect to the scries of
tubes above it, as it did with respect to the lower series it has just left.
In like manner it traverses each series of tubes till it has reached the top
of the body of the boiler, from which it passes to the steam chests or 3
superheaters.

page_text: describe with reference to the accompanying Drawings the manner in
which the same is to be performed.
Figure 1 represents in longitudinal vertical section and Figure 2 in
cross section a stationary boiler constructed according to my Invention;
Figure 3 is a front clevation of the same, and Figure 4 is a plan of
the upper side of the same; Figure 5 is a horizontal section taken on the
line E, F, Figure 1, with the firc-grate omitted on one side, Figure 6 is
a horizontal section taken on the lino G, H, Figure 2; and Figure 7
is a horizontal section taken on the line I, J, Figure 2. The same letters
of reference arc used to indicate the same parts in Figures 1, 2, 3, 4, 5, 6,
and 7.
a, a, represents the body of the boiler extending the entire distance
between the side walls h, h, Figure 2. The top and bottom of the
boiler a arc made of cast or wrought iron, and the plates a³, a², are
firmly connected together by bolts and tubes a³. The body a is divided
throughout a portion of its height into two compartments by the vertical
partition a. In the front plato a are holes opposite the tubes, which
holes are closed by the metal plugs a screwed into them. b, b, b, aro
the tubes affixed to the tube plate a¹ by ferrules b¹. The ends b² of the
tubes 6 are closed by hemispherical caps, and the said tubes 6 are divided
into two compartments by the longitudinal plates or partitions 6³
extending from near the ends to the tube plate a', where they are
provided with the enlarged or funnel-shaped mouth-pieces 6', which
extend from the lower compartments of the tubes, and traversing the
partition at to which they are affixed open into the front compartment
of the body of the boiler a. c, c, is a plate traversed by the tubes b,
and supporting the ends of the said tubes. d is a curved plate for pre-
venting the water in the boiler from rising with the steam. e, e, are
two cylindrical steam chests for drying the steam generated in the boiler.
Each of the said steam chests is composed of two cylinders e and e¹, one
within the other. The front ends of the said cylinders e and e¹ arc
affixed to the plate a¹ of the body of the boiler a, and the cylinder e
communicates with the upper part of the body of the boiler by the
perforated pipe e². The two cylinders e, e', which communicate onc
with the other by apertures et are closed at their outer ends by a plate e³,
and in the annular space between the said cylinders e, e¹, is fixed a
helix e*, so as to form with the sides of the cylinders a helical passage
for the steam. The two steam chests e, e, communicate with tho

page_text: superheater by means of the pipes f', f¹, as seen at Figure 2. The
construction of the superheater being similar to that of the drying
chests c, c, a further description of it is unnecessary.
9, Figure 1, is a steam cock, which communicates with the super-
licater by means of the pipe g¹. h, h, and h¹ are the side and back
walls of the boiler. The said walls, as well as the furnace walls 2, 2, i,
are made of brickwork. The roof j, j, is formed of a double casing of
slicet metal filled in with a non-conducting material, such as coke dust.
% is the chimney, provided with a damper composed of the wings,
shutters, or louvres k¹ jointed to the frame . To the axes of the said
wings, shutters, or louvres are affixed the arms ³ connected to the
bar k by means of which the shutters may be opened or closed at
-pleasure.
The boiler represented is provided with a smoke-consuming furnace.
1, 1, are the two fire-grates, between which a space is left for the ad-
mission of air. m, m, m, are flues for the admission of air to the
furnace. The said flucs are formed in the walls 2, 1, and open at one end
into the furnace below the grate P, P, whilst their other ends open in
front of the furnace, where suitable dampers p regulate the admission of
air is a hopper for feeding the fuel on to the grate 7 o is the ash-
pit, which is closed in front by the door o¹.
Figure 8 represents in cross section taken through the line A, B,
Figure 9, a portable or semi-stationary boiler constructed according to
my Invention; Figure 9 is a longitudinal section of the same taken on
the line C, D, Figure 8; Figure 10 is a front elevation of the same,
showing one side of the said boiler without its exterior casing; Figure 11
represents one half of the section taken on the line E, F, Figure 8; and
Figure 12 is a partial section taken on the line G, II, Figure 8, and
partially a horizontal view of the boiler.
a, a, is the body of the boiler; a¹, the tube plate, a², the front plate,
which plates are connected together by stay bolts a³, a' is the metal
partition which divides the body of the boiler a into two parts through a
portion of its height, a' are plugs closing the holes opposite the tubes;
b, b, are the tubes affixed to the tube plate a' The said tubes are divided
into two compartments through a portion of their length by the longi-
tudinal partitions, b³, b', are mouth-picces by means of which the lower
pait of the tubes communicates with the front compartment of the body

page_text: of the boiler a; c, c, is the back plate supporting the tubes; d is a
curved plate to prevent the water from rising with the steam; e is the
drying cylinder for drying the steam. The said cylinder is constructed
in the same manner as those represented in Figures 1 and 2 except that
the steam is made to enter the outer cylinder, from whence it passes into
the inner cylinder e', and is discharged through the pipe g¹; h, h, are the
side and back walls, which, as well as the roof 3, are composed of a
double casing of sheet metal filled in with any suitable non-conducting
material, is the chimney provided with the dampers k³, as in the
stationary boiler herein-before described, 2 is an ordinary furnace sur-
rounded by fire-brick walls ; is the grate, n, the furnace door; o, the
ash-pit; o, the door of the ash-pit, and p is a damper to regulate the
admission of air above the grate 7.
Figure 13 represents in longitudinal section a marine boiler con-
structed according to my Invention; Figure 14 is a cross section of the
same taken on thic line C, D, Figure 13, Figure 15 is a horizontal
section of the same taken partly through the line E, F, Figure 14, and
partly through the line G, H, Figure 13.
The marine boiler represented in Figures 13, 14, and 15 is similar to
the stationary boiler represented in Figures 1, 2, 3, 4, 5, 6, and 7, except
in respect of the outer walls surrounding the boiler and furnace and the
bottom of the furnace The walls, 2, and the bottom of the furnace
are composed of a double casing of sheet metal forming water spaces
communicating with the body of the boiler a The walls h round the
boiler and the roof 3 are composed of a double casing of sheet metal
filled in with any suitable non-conducting material. The furnace is an
ordinary furnace. The other parts of the said boiler being similar to
those described in respect of Figures 1 to 7 of the Drawings, and being
marked with the same letters of reference it is unnecessary to describe
them further.
Figure 16 represents in cross section and in side clevation a modifica-
tion in the construction of the plugs used for closing the apertures in the
front plate a³ of the boiler facing the tubes. The said plug consists of
a cast-iron circular plate A, which fits into the said aperture, and is fixed
to the boiler plate as by the three-armed tic-piece c, c, c, the central
11
1
1

page_text: The tubes used in connection with my boilers may be of the character
of those shown at 6, Figure 1, that is to say, closed at their outer ends
and divided longitudinally by horizontal or vertical partitions into two
compartments communicating one with the other, or the tubes may
be made double, as seen at Figure 17, where a represents a part of the
body of the boiler, a³, the tube plate; a², the outer plate; and a', the
partition dividing the said body a, b is the outer tube affixed to the tube
plate a¹ and closed at its outer end 6º; and 6' is an inner tube affixed by
its forc end to the partition at and opening into the front compartment
of the body a.
The said inner tube 6¹ extends to within a short distance
of the closed end 63 of the tube b. Or tubes bent in siphon or U shape
may be used as seen at 6, Figure 18. In this case one end of the tubo b
16 provided with a mouth-piece 6', which passes through the plate a' into
the front compartment of the body of the boiler a, whilst the other end
of the tube & extends no further than the tube plate a¹, to which it is
affixed by a ferrule 2 or otherwisc Or the tubes may be set in scrics, as
shown at Figure 19. The said tubes are in this case disposed in two
series of tubes b, b', one above the other The lower series 6' in which
steam is to be gencrated is composed of tubes similarly arranged to the
tubes b, Figure 1. The upper series 6 (Figure 19) is composed of similar
tubes unprovided with mouth-pieces, and extending no further than tho
tube plate a¹
The said tubes are fitted with partitions or plates 6³,
dividing them horizontally into compartments, but the ends of the said
plates instead of being provided with funnel-shaped mouth-picces are
connected with the horizontal partition 6 in the body of the boiler. The
lower part of the body of the boiler a, as far as the last row of water
tubes, is similar in all respects to that represented at Figure 1, but it is
there divided horizontally throughout its length by the partition a
rivetted to the tube plate a' and to the vertical partition at. The tubes
communicate with the tubes ¹ by means of an aperture a formed in the
partition a. Through the said aperture a the water and steam com-
pressed by ebullition escape into the fore compartment of the body of
the boiler, where the water acted upon by gravity falls and mixes with
the feed water, whilst the steam separates and tends to rise to the top of
the body a of the boiler; but as it is important that the said steam should
be deprived as much as possible of the water it contains its upward
motion is arrested by a metal partition a', which is an extension of the
plate in the tubes b. The steam is thus caused to traverse the holes
a³, a³, in the partition a' and to pass through the lower half of the

page_text: tube b to the end b, where it rises to above the plate 6 and returns
through the upper half of the said tube into the body of the boiler a,
which is divided by partitions. It then passes into other arrangements
of tubes disposed similarly, and performs a similar circuit in the said
tubes, and continues passing from series to series till it has entered the
last serics,, from which it is finally discharged into the top space of the
body of the boiler, and from thence passes into the superheaters or
tubes, and continues passing from series to series till it has entered the
last serics, from which it is finally discharged into the top space of the
body of the boiler, and from thence passes into the superheaters or
dryers.
Having now described the nature of my said Invention and the manner
in which the same is carried into effect, I wish it, to be under-
stood that I do not confine myself to the precise details herein-before
described and illustrated in the accompanying Drawings, as the same
may be varied without departing from the nature of the said Invention;
but I claim as my Invention of “ Improvements in Steam Boilers or
Generators and in their Furnaces,"-
Firstly. The general construction and arrangement of steam boilers or
generators herein-before described and illustrated in the accompanying
Drawings (that is to say), a boiler composed of a rectangular or other
shaped case or body divided throughout part of its height into two com-
partments by a metal partition, and from one side of which case or body
projects a series of tubes closed at their outer ends, each of the said tubes
being divided into two compartments by a longitudinal plate or partition
extending from near the closed end of the said tube to the tube plate of
the case or body of the boiler, where the said tube is provided with a
mouth-piece, by which one of the compartments of the said tube com-
municates directly with one of the compartments in the body of the
boiler, the other compartment of cach tube being in communication
with the second compartment in the body of the boiler, the said arrange-
ment producing a complex circulation in each tube, and thus causing
the water in the boiler to flow in two different currents, one containing
steam and the other none or but little.
Secondly The drying chests or cylinders for drying the steam and the
superheaters herein-before described and illustrated in the accompanying
Drawings (that is to say), drying chests or superheaters formed of two
6 cylinders one within the other, communicating one with the other by

page_text: the two cylinders being fitted with a helix forming in the said space a
helical passage or channel, in which the steam is dried or superhcated as
required.
Thirdly The combination with the boilers hercin-before described of
a smoke-consuming furnace with flues arranged in the walls of the
furnace, essentially as heroin-before described and illustrated in Figures 1,
2, 3, and 5 of the accompanying Drawings.
Fourthly The modifications in the construction and arrangement of
the boiler tubes as herein-before described and illustrated in Figures 17,
18, and 19 of the accompanying Drawings.
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In witness whereof, I, the said Marie Léon Buret de Longagne,
have hercunto set my hand and seal, this Twenty-eighth day of
September, in the year of our Lord-One thousand eight hundred
and seventy-five.