IMPROVEMENTS IN AND RELATING TO STEAM-BOILERS
Year: 1885

page_text: We ETIENNE LAGOSSE, and JEAN BOUCHÉ, both of Paris, France, do hereby
declare the nature of our invention for "IMPROVEMENTS IN AND RELATING TO
STEAM-BOILERS "to be as follows:-
This invention relates to an improved multitubular steam-boiler composed of a
number of sections each of which comprises two or more tubes.
The said boiler is characterized by its general arrangements and by the following
essential features viz:-
1st That the circulation of the water and steam take place in a rational manner
that is to say, the water and steam pass in the same direction, thereby enabling a
rapid circulation to be obtained, owing to which the heat of the furnace is well
utilized; moreover the direction of circulation of the fluid mixture is contrary
to that in which the products of combustion pass thus providing for methodic
heating.
2nd That the course traversed by the steam, from the tubes to the steam receiver
is as short as possible and in a substantially vertical direction; and that the
conduits through which the steam passes in its passage do not present any con-
tractions or abrupt changes of direction, which arrangements greatly facilitate the
upward passage of the steam and consequently its production.
3rd That the evaporating surface is comparatively large which permits a rapid
generation of steam.
4th That the general arrangement, although the apparatus is formed of sections
having two or more tubes, and presenting no contraction in the connecting permits
the tubes to be placed near to and overlapping one another, which arrangement has
the advantage of causing the flames and heated gases to act in a very advantageous
manner upon the said tubes.
5th That one or more special feed water heaters part of which can if necessary
be utilized as superheaters or dry-steam apparatus, permit all the heat which it is
possible to retain from the products of combustion to be utilized prior to the passage
of the latter into the chimney.
These various features will be hereinafter described.
We are aware that multitubular boilers bave heretofore been constructed, some
of which possess certain of the advantages above set forth; but none of these

page_text: multitubular boilers unite all the features which we have enumerated, and they
cannot do so by reason of the nature of their construction.
Several multitubular boilers have been constructed in such a manner that the
water and steam always pass in the same direction and in the contrary direction
to the gases of combustion; but then these boilers have only one tube for each
section or if they have several tubes they do not combine the last four features
enumerated above.
Some of the last mentioned features have been possessed separately in certain
types of multitubular boilers, but not collectively, as in our improved boiler.
Our improved boiler is composed essentially of the following principal parts,
viz:-
Of a horizontal cylindrical water and steam reservoir, arranged longitudinally of
the boiler at the upper part and away from the flues for the escape of the products
of combustion, so that in case of repairs the said reservoir may be dismounted
without interfering with the masonry of the flues.
Of two or more steam collectors placed horizontally and transversely of the
boiler upon the front, one of which collectors is in communication with the
cylindrical reservoir. These collectors are connected by means of two vertical
pipes which can be easily dismounted. The boiler, as will be seen hereafter, is
provided with as many groups of sections as there are steam collectors. This
division has for its object to augment the evaporating surface and to produce with
equal heating surfaces a greater quantity of steam than heretofore.
Of feed-water collectors, equal in number to the steam collectors, placed horizon-
tally and transversely at the rear of the boiler and in direct communication with
the rear and lowest part of the cylindrical reservoir by means of vertical pipes
which can be easily dismounted and of tubular generating sections the number and
dimensions of which vary according to the power of the boiler.
Each of the said sections is composed of two or more tubes of iron or other metal
placed one above the other but in different vertical planes so as to overlap one
another in the general arrangement. These tubes are united and placed in
communication at their two extremities by means of connecting boxes of cast-
iron, cast steel or other suitable metal, and of a special form, which form permits
vertical faces to be obtained in front and in rear of the boiler despite the great
obliquity of the tubes. This oblique arrangement of the tubes facilitates rapid
circulation of the water and steam in the boiler.
The exteriors of the extremities of the tubes are slightly conical and the openings
in the connecting boxes fit the ends of these tubes which are inserted therein; the
parts of the tubes which penerate into the interior of the boxes are expanded so
as to form small annular enlargements within the boxes, which construction gives
great stability and forms perfectly tight joints.
Besides the connecting. boxes serving to unite the tubes of the sections other
boxes serve to place the several sections in communication. The connection
between the two sets of connecting boxes is formed by means of small iron tubes
the diameter of which is at least equal to that of the tubes of the sections.
This construction has the advantage of obviating the formation of contracted
passages which are always prejudicial to an active circulation of the water and
steam.
This arrangement cannot be effected in boilers having only one tube for each
section nor in most other multitubular boilers, unless the tubes are at a considerable
distance apart this arrangement however is bad from the point of view of the
utilization of the heat.
The absence of contracted passages is one of the points which characterize our
boiler. We may say that we have no intention of claiming the system of uniting
the tubes in their connecting boxes, but we consider, as forming part of our
invention the arrangement of the tubes of the same section at different heights,
which arrangement has enabled us to give to the connecting boxes an inclined
position approaching the vertical in order to obviate abrupt changes of direction in
•

page_text: the passage of the steam, when once the latter leaves the tubes.. This essential
condition would not be realized with horizontal connecting boxes.
Each joint is tightened by two or four bolts which ensure absolute safety. The
heads of these bolts are held in slots formed in the metal of the tube connecting
boxes.
As already stated, we employ in the same boiler two or more steam collectors
and as many feed-water collectors, and we thus divide our boiler into groups of
tubes separated by portions of fire-bricks; this is a feature which, independently
of its combination with the others, is new and the purpose of which is to augment
the generation of steam as will be seen hereinafter.
As all the groups of tubes are identical, it will be sufficient to describe a single
group for instance the lower one of a boiler. This group is fed at the lower part
of its rear face by a feed collector. The steam which escapes from the tubes passes
directly through the connecting boxes into the lower steam collector through a
number of orifices equal in sectional area to that of the sections which are in the
same horizontal row. Now as these orifices, as stated, have a section at least equal
to the section of the tubes in order to obviate the reduction of the passages, the
area for the liberation of steam, in the collector should at least be equal to one
quarter of the total sectional area of four horizontal rows of tubes of the lower
group. In order that the circulation shall not be obstructed the sectional area of
the two tubes which unite the steam collectors is equal to that of all the tubes of a
horizontal row.
The upper group is fed from a different water collector to the first group, and
its steam is evolved in a different collector. As this upper group is heated less
than the group below, it produces, proportionally to the heating surface, less steam
and can comprise a greater number of horizontal rows of tubes for the same steam-
evolving surface; in this case there are six horizontal rows of tubes, and the area
are of the surface for the evolution of steam is the sixth of the total section of
the tubes.
If, then, an average is taken between the areas for the evolution of steam in
the two groups, a sectional area is obtained, which is equal to one-fifth of the
section of all the tubes of the generator (These numbers are not meant to be in
any way absolute.)
Never before have like proportions been arrived at in actual multitubular
boilers, and this result is due to the division into distinct tubular groups.
We will now proceed to describe our system of heater. This heater may be
placed upon one side of the generator, or it can be behind the same or on both
sides according to the room at disposal and the importance of the said heater. In
the case of a marine boiler it can even be placed above the boiler.
The heater is formed of sections like the generator, only the sections of the
heater are of rectangular form and constitute U-shaped tubes. There may be only
one section for each horizontal row of tubes, or there may be several.
Boxes at the rear of the tubes place the latter in communication. Openings in
these boxes opposite to the tubes are closed by means of a cast iron cover having a
conical joint. The joint is made from the inside to the outside in such a manner
that the more pressure there is inside, the tighter the joint is.
At the front of the furnace the tubes of each section simply pass through a metal
plate which can if required have a flange. Connecting boxes unite the sections
horizontally between them by means of taper joints which fit directly the
extremities of the tubes; tightening bolts and cross-pieces keep them in place.
Curved boxes serve as connections between the various horizontal rows, the
curve of the boxes being such as to allow the tubes to approach each other as near
as possible.
By separating a certain number of tubes of the upper part of the feed water
heater, a steam super beater or drying device may be formed by putting them into
communication with the upper part of the steam reservoir.

page_text: As regards the furnace, it does not present any particular feature; it is inclined
towards the rear and comprises an air-channel behind the bridge operated from the
front of the boiler by a rod. This air channel serves to ensure the complete
combustion of the fuel in the furnace.
A casing of metal or brickwork, which is completely independent of the parts of
the boiler under pressure, surrounds the boiler, and is provided with doors for
affording easy access to all the parts.
It will thus be seen from the foregoing description that our generator actually
possesses the features indicated at the commencement of this specification, which
features as a whole, constitute the novelty of our apparatus, because no actually
existing multitubular boiler having sections composed of several tubes possesses
them all at the same time.
We have demonstrated that our multitubular boiler is characterized by the
simultaneity of the following conditions.
The passage of the water and steam in the same direction this fluid mixture
passing through all the tubes from the rear of the generator towards the front by
reason of the parallelism of the said tubes.
The course traversed by the steam formed, on leaving the tubes and entering
the reservoir is as short as possible because it passes in nearly a vertical direction.
Moreover, great freedom of circulation is obtained by obviating any abrupt change
of the sectional area of the passages all the orifices formed in the boxes being of the
same diameter as those of the tubes, which cannot be obtained in most of the
present multitubular boilers without placing the tubes at a considerable distance.
apart which arrangement is detrimental to a good utilization of the heat.
Considerable surface is obtained for the evolution of steam by reason of the
division of the tubes into distinct groups by the interposition of a variable number
of water and steam collectors.
The employment of an improved heater formed of a series of V shaped tubes
forming a row of horizontal serpentine pipes in communication with each other
these tubes being formed in front as well as in the rear of the furnace in a novel
manner.

page_text: We, ETIENNE LAGOSSE and JEAN BOUCHÉ both of Paris France, do hereby
declare the nature of our invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to a multitubular steam-boiler composed of a number of
sections each of which comprises two or more tubes.
The said boiler is characterized by its general arrangements and by the following
essential features viz;―
1st The circulation of the water and steam takes place in a rational manner
that is to say, the water and steam pass in the same direction thereby enabling a
rapid circulation to be obtained, owing to which the heat of the furnace is well
utilized; moreover the direction of circulation of the fluid mixture is contrary
to that in which the products of combustion pass thus providing fór methodic
heating.
2nd The course traversed by the steam from the tubes to the steam receiver is
as short as possible and in a substantially vertical direction; and the conduits
through which the steam passes in its passage do not present any contractions or
abrupt changes of direction, which arrangements greatly facilitate the upward
passage of the steam and consequently its generation.
3rd The evaporating surface is comparatively large which permits a rapid
generation of steam.
4th The general arrangement, although the apparatus is formed of sections
having two or more tubes, and presenting no contraction in the connecting boxes,
permits the tubes to be placed near together, and to overlap one another, which
arrangement has the effect of causing the flames and heated gases to act in a very
advantageous manner upon the said tubes.
5th One or more special feed water heaters part of which can if necessary, be
utilized as superheaters or dry steam apparatus, permit all the heat which it is
possible to retain from the products of combustian to be utilized prior to thẻ
passage of the latter into the chimney.
These various features will be hereinafter described.
We are aware that multitubular boilers have heretofore been constructed, some
of which possess certain of the advantages above set forth; but none of these
multitubular boilers unite all the features which we have enumerated, and more-
over they cannot do so by reason of the nature of their construction.
Several multitubular boilers have been constructed in such a manner that the
water and steam always pass in the same direction and in the contrary direction
to the gases of combustion; but then these boilers have only one tube for each
section, or, if they have several tubes, they do not combine the last four features
enumerated above.
Some of these last mentioned features have also been possessed separately
in certain types of multitubular boilers, but not collectively as in our improved

page_text: In the accompanying drawings we have shown the general arrangements and
the details of our improved boiler.
Figure 1 is a front view of the said boiler some of the enclosing plates being
.removed.
Figure 2 is a longitudinal section of the same.
Figure 3 is a rear view.
Figure 4 is a front view showing the relative arrangement of several sections
and the boxes connecting the same.
Figure 5 is a section on the line A, B, C, D Figure 4.
Figure 6 is a section on the line E F Figure 4.
Figure 7 is a front view of the water heater hereinafter described some of the
boxes uniting the tubes of the same being removed.
Figure 8 is section of the same on the line G H.
Figure 9 is a front elevation of a marine boiler constructed..according to this
invention the casing door on the right being removed.
Figure 10 is a vertical section of the same.
Figure 11 represents a sectional rear view of the same.
Figure 12 illustrates in vertical section and in front view the mode of jointing
the tubes of the lateral walls in their connecting boxes.
Our improved boiler is composed essentially of the following principal parts
viz Of a cylindrical water and steam reservoir I placed horizontally and longi-
tudinally at the upper part of the boiler and away from the flues for the escape of
the products of combustion, so that in case of repairs the said reservoir may be
dismounted without interfering with the masonry of the flues.
Of two or more steam collectors J, J¹ placed horizontally and transversely of
the boiler upon the front, one of which collectors is in communication with the
cylindrical reservoir I. These collectors are connected by means of two vertical
pipes K K of large section and which can be easily dismounted. The boiler as
will be seen hereafter is provided with as many groups of sections as there are
steam collectors. This division has for object to augment the evaporating surface
and to produce with equal heating surfaces a greater quantity of steam than
heretofore.
Of feed-water collectors L L³ the number of which is equal to that of the steam
collectors the said collectors being placed horizontally and transversely at the rear
of the boiler and in direct communication with the rear and lowest part of the
cylindrical reservoir I by means of vertical pipes M M which can be easily
dismounted, and
Of tubular generating sections the number and dimensions of which vary
according to the power of the boiler.
Each of the said sections is composed of two or more tubes N N¹ of iron or other
metal placed one above the other but in different vertical planes so as to overlap
one another in the general arrangement. These tubes are united and placed in
communication at their two extremities by means of connecting boxes O herein-
after termed tube connecting boxes, of cast iron, cast steel or other suitable metal,
and of a special form which form permits vertical faces to be obtained in front
and in rear of the boiler, despite the great obliquity of the tubes. The oblique
arrangement of the tubes facilitates the rapid circulation of the water and steam
in the boiler,
The exteriors of the extremities of the tubes are slightly conical (see Figure 5)
and the entrance openings in the tube connecting boxes Ŏ fit the ends of these
tubes, which are inserted therein, the parts of the tubes which penetrate into the
interior of the boxes are expanded so as to form small annular enlargements P
(Figure 5) within the boxes which construction gives great stability and forms
- perfectly tight joints.
Besides the connecting boxes O serving to unite the tubes of each section, other
connection boxes Q hereinafter termed section connecting boxes serve to place
the several sections in communication. The connection between the two sets of

page_text: connecting boxes O, Q, is formed by means of small iron tubes R (Figure 5) the
diameter of which is at least equal to that of the tubes N N¹ of the sections.
This construction has the advantage of obviating the formation of contracted
passages which are always prejudicial to an active circulation of the water and
steam.
This arrangement cannot be effected in boilers having only one tube for each
section, nor in most other multitubular boilers, unless the tubes are at a con-
siderable distance apart, this latter arrangement however is bad from the point of
view of the utilization of the heat.
The absence of contracted passages is one of the points which charactize our
boiler. We have no intention of claiming the system of uniting the tubes in their.
connecting boxes O and Q, but we consider as forming part of our invention the
arrangement of the tubes of the same section at different heights, which arrange-
ment has enabled us to give to the connecting boxes O an inclined position
approaching the vertical, in order to obviate abrupt changes of direction in the
passage of the steam, when once the latter leaves the tubes. This essential
condition would not be realized with horizontal connecting boxes.
Each joint is tightened by two or four bolts (figure 4,) which ensure absolute
safety. The heads of these bolts are held in slots formed in the metal of the tube
connecting boxes O and represented in figures 4, 5 and 6.
As already stated, we employ in the same boiler two or more steam collectors J J¹
and as many feed-water collectors L L. We thus divide our boiler into groups
of tubes separated by partitions of fire-bricks; this is a feature which, independently
of its combination with the others, is absolutely new and the purpose of which is
to augment the generation of steam as will be seen hereinafter.
The boiler given as an example in the drawing comprises two of these groups.
As all the groups of tubes are identical, it will be sufficient to describe a single
group, for instance the lower one of a boiler.
As appears from figure 1 the lower group is fed at the lower part of its rear face
by a feed collector L. The steam which escapes from the tubes passes directly
through the boxes O and Q into the lower steam collector J through a number of
orifices equal in sectional area to that of the tubes of the sections which are in the
same horizontal row. Now as these orifices, as stated, have a section at least equal
to the section of the tubes in order to obviate the reduction of the passages, the
area for the liberation of steam in the collector J should at least be equal to
one quarter of the total sectional area of four horizontal rows of tubes of the lower
group. In order that the circulation shall not be obstructed, the sectional area of
the two tubes K K which unite the collectors J J¹ is equal to that of all the tubes
of a horizontal row.
The upper group of sections is fed from the water collector L' and its steam is
evolved in the collector J¹. As this upper group is heated less than the group
below, it produces, proportionally to the heating surface, less steam and can
comprise a greater number of horizontal rows of tubes for the same steam evolving
surface. In the present instance there are six horizontal rows of tubes, and the
area of the surface for the evolution of steam is the sixth of the total section of
the tubes. If, then, an average is taken between the areas for the evolution of
steam in the two groups a sectional area is obtained, which is equal to one-fifth
of the section of all the tubes of the generator. (These numbers are not meant to
be in any way absolute).
Never before have like proportions been arrived at in multitubular boilers, and
this result is due to the division into distinct tubular groups.
We will now proceed to describe our system of heater.
The heater shown in the drawing is placed upon one side of the generator, but it
is to be understood that it can be behind the same or partly on both sides according
to the room at disposal, and the importance of the said heater. In the case of a
marine boiler it can be placed above the boiler.}
"

page_text: •
The heater is formed of sections like the generator, only the elements or sections
of the heater are of rectangular form and constitute U-shaped tubes.
As shown in figures 1 and 3 there is only one section for each horizontal row of
tubes but there may be several as shown in figures 7 and 8.
Boxes S at the rear of the tubes V place the latter in communication. The
openings in these boxes opposite to the tubes are closed by means of cast iron
covers U having conical joints. The joints are made from the inside to the outside
in such a manner that the more pressure there is inside the tighter the joints are.
At the front of the furnace the tubes of each section simply pass through a metal
plate Y, which can, if required, have a flange for enabling it to rest upon the
section below. Connecting boxes T unite the sections horizontally by means of
taper joints which fit directly the extremities of the tubes; tightening bolts and
cross-pieces keep them in place.
Curved boxes T¹ serve as connections between the various horizontal rows the
curve of the boxes being such as to allow the tubes to approach each other as near
as possible, as is clearly shown in figure 1.
By separating a certain number of tubes of the upper part of the feed water
heater, a steam super heater or drying device may be formed by putting them into
communication with the upper part of the steam reservoir I.
As regards the furnace, it does not present any particular feature, it is inclined
towards the rear and comprises an air channel W behind the bridge operated from
the front of the boiler by a rod X. This air channel serves to ensure the complete
combustion of the fuel in the furnace.
A casing of metal or brickwork, which is completely independent of the parts of
the boiler under pressure, surrounds the boiler, and is provided with doors for
affording easy access to all parts of the generator.
It will thus be seen from the foregoing description that our generator actually
possesses the features indicated at the commencement of this specification, which
features as a whole, constitute the novelty of our apparatus, because no actually
existing multitubular boiler having sections composed of several tubes, possesses all
the said features at the same time.
We have demonstrated that our multitubular boiler is characterized by the
simultaneity of the following conditions.
The passage of the water and steam in the same direction, this fluid mixture
passing through all the tubes from the rear of the generator towards the front, by
reason of the parallelism of all the said tubes.
The course traversed by the steam formed, on leaving the tubes and entering the
reservoir, is as short as possible, because it passes in nearly a vertical direction
owing to the absence of horizontal connecting boxes. Moreover, great freedom of
circulation is obtained, by obviating any abrupt change of the sectional area of the
passages, all the orifices formed in the boxes being of the same diameter as those of
the tubes, which advantage cannot be obtained in most of the present multitubular
boilers without placing the tubes at a considerable distance apart, which arrangement
is detrimental to a good utilization of the heat.
Considerable surface is obtained for the evolution of steam, by reason of the
division of the tubes into distinct groups by the interposition of a variable number
of water and steam collectors.
The employment of an improved heater formed of a series of U-shaped tubes
constituting a row of horizontal serpentine pipes in communication with each other
these tubes being joined in front as well as in the rear of the furnace in a novel
manner.
The modification of our invention represented in Figures 9, 10, 11 and 12 does
not differ essentially from our land boiler, herein before described, but is simply a
modification of the latter, which renders it applicable for marine purposes.
In the land boiler the water is supplied through the medium of tubes M M and
water collectors L L in such a manner that the feeding takes place in the tubular

page_text: group from below upwards. In our marine boiler, on the contrary, the feeding
takes place directly through the tube connecting boxes O and section connecting
boxes downwards, from the water collector L placed at the upper part of the
tubular group to the collector L placed at the lower part of the boiler. This
arrangement has the advantage, in case the rolling or tossing motion reverses the
direction of the inclination of the tubes, of permitting the disengagement of the
steam generated during this reversal, directly from the rear of the boiler.
It is to be understood that in case of any liability of the lower elements not
being sufficiently fed, we can make use of return water tubes similar to the
tubes M M of the land boiler: In this manner the feeding of the tubes takes.place
simultaneously from the upper and lower parts of the boiler.
Another characteristic modification which has been necessitated by the con-
struction of our marine boiler consists in placing the water and steam reservoir I
transversely at the rear of the boiler, in order to reserve at the top and front of
the boiler a sufficient space for arranging the feed water heater and the steam
superheater.
This arrangement has the advantage of permitting the construction of our
generator in a minimum space, it moreover enables the easy cleaning of the tubes,
and a direct and consequently more energetic draught of the chimney.
This general combination of the generator and feed water heater enables all the
heat which it is practically possible to retain to be utilized before the gases of
combustion escape through the chimney.
The cylindrical reservoir I, being placed at the rear of the boiler in compliance
with the preceding considerations, is connected to the upper steam collector J by
means of a series of horizontal tubes placed side by side and leaving between them
only the space absolutely necessary for permitting the escape of the products of
combustion in order to render uniform, in all parts of the boiler, the ascention of
the gases from the furnace and thus to heat equally all parts of the tubular group.
As shown in Figures 9, 10, 11 and 12 the sides of the furnace and of the lower
tubular group are formed of sections comprising two or a greater number of tubes
having the same inclination as those of the main tubular groups.
The tubes of these side sections, represented on an enlarged scale in Figure 12,
are narrowed at the two ends in order to enter vertical boxes, and to lie close to
each other.
.
With the construction hereinbefore described a multitubular boiler is provided
having an internal furnace.
A feature which likewise constitutes a novelty in our system of marine boiler is
its general arrangement as represented in the drawings.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
First. A sectional multitubular boiler, each section of which comprises two or
more tubes connected substantially as described.
Second. The employment of the steam collectors J J' and an equal number of
water collectors LL, the said collectors being respectively connected by means of
tubes K K and M M, the total section of which is equal, two and two, to that
of all the generating tubes N N¹ of the same horizontal row, the object of this
arrangement being to divide the boiler into several distinct tubular clusters, in
order to give activity to the circulation of the fluid mixture and thus augment the
generation of steam, as described.
Third. The equality between the diameters of the orifices of the connecting
boxes O and Q and tubes N N' and if necessary the superiority of the former over
the latter, obtained by the oblique disposition of the said boxes, for the purpose of
obviating any reduction of section and consequently any losses prejudicial to a good
circulation; these said tubes being arranged so as to overlap one another and lie

page_text: •
.as near together as possible, in order to utilize the greatest part of the heat of the
products of combustion.
Fourth. The arrangement of the parts in such a manner that the current of
steam, after its exit from the tubes passes in nearly a vertical direction thus
facilitating its evolution, this being obtained by the obliquity of the boxes O and Q
none of which are horizontal.
Fifth. The feed-water heater (one part of which can serve, if necessary, as a
steam dryer or superheater) formed of sections comprising two or more tubes V,
constituting superposed horizontal series of U-tubes, the connections of which are
obtained, at the rear through the medium of rectangular and horizontal boxes S
fixed directly upon these tubes by conical joints, and annular rims carrying conical
stoppers, and, these sections at the front being supported in metallic plates Y with
or without rims, and being united between one another directly by means of
commnicating boxes T having conical joints and tightening bolts and cross-pieces,
as described.
Sixth. In a marine boiler, the mode of feeding the tubular groups from the
upper and rear part of the generator directly through the communicating and
connecting boxes, in order to permit, during the extreme rolling of a ship in a
storm, the disengagement, of the steam at the rear of the boiler, and connecting, if
desired, the lower water collector with the transverse water and steam reservoir.
Seventh. In a marine boiler, the upper water and steam reservoir arranged
transversely at the rear of the boiler and united by a series of horizontal tubes to
the upper steam collector.
Eighth. In a marine boiler, the arrangement of the feed water heater and steam
dryer or superheater above the generator, and in front of the water and steam
reservoir, for the purpose herein before described.
Ninth. In a marine boiler, the formation of walls of the furnace, and of the
lower tubular section, of elements or sections comprising two or more tubes placed
side by side in the same vertical plane, the ends of the said tubes being reduced in
diameter, so that when jointed in their connecting boxes they will be close
together.