improvements in Marine water-tube Bollers.
Year: 1899

page_text: improvements in Marine water-tube Bollers.
I, ETIENNE LAGOSSE, of 82, Rue St. Lazare, Paris, in the Republic of France,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to a marine boiler comprising a horizontal cylindrical
body and one or two heating-tubes placed below the said cylindrical body to
which they are connected by bundles or clusters of straight tubes of the same
length. The tubes of each bundle are fitted into tube-plates forming an integral
part of the wall of the cylindrical body and of the heating-tubes; where two
heating-tubes are employed the bundles together form the two legs or limbs of
an inverted V below which there is arranged the furnace grate.
The construction of my boiler has for its object to produce a thoroughly
methodical circulation of the water and of the gases of combustion. To this end
the tubes of each bundle are divided longitudinally into two sets or layers by a
screen suitably perforated; the tubes arranged on the inside of this screen or
on the side of the furnace have a large diameter and have between them relatively
large free spaces for the combustion of the gases; the tubes arranged on the
outside of the screen have on the contrary a small diameter and are close together.
Furthermore, on the inside of the cylindrical body there is arranged a device
for accelerating the circulation, the said device consisting of a partition, chimney
or envelope completely separating the ascending currents issuing from the
tubes next the furnace from the descending currents directed towards the
external return tubes.
This circulation accelerator is composed in most cases of a partition in the
form of an inverted trough fixed above the orifices of the large tubes upon the
tube-plate and of one or more cylindrical or oval chimneys secured to this parti-
tion. The chimney or chimneys extends or extend to a point either above or
below the level of the water in the boiler.
The boiler and the heating-tubes are only in direct contact with the furnace
gases at the parts forming the tube-plates.
The water in the large tubes being raised to a high temperature ascending
currents are formed in the said tubes whilst the colder water of the boiler
descends through the small tubes and mixes with that in the heating-tubes
which is drawn up in its turn through the large tubes by the ascending current.
On reaching the cylindrical body all the ascending streams of water issuing
from the large tubes are united under the partition and they rise through the
chimneys; the water from these chimneys falls laterally leaving the steam which
it carries with it and redescends into the boiler through the tubes of small
diameter. There is never any confusion or direct contact between the ascending
and descending currents; as a result of this the circulation of the water is very
active and the evaporative power of the boiler, as also its efficiency, is raised to
the maximum.
Above the one or more chimneys placed in the cylindrical body there are fixed

page_text: sheet metal caps having for their object to break any upwardly projected streams
and to avoid water being carried into the steam dome.
The invention can be similarly applied to a generator having only one
heating-tube.
Dated the 17th day of January 1899.
Improvements in Marine Water-tube Boilers.
I, ETIENNE LAGOSSE, of 82, Rue St. Lazare, Paris, in the Republic of France,
Engineer, do hereby declare the nature of this 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 marine boiler comprising a horizontal cylindrical
body and one or two heating-tubes placed below the said cylindrical body to
which they are connected by bundles or clusters of straight tubes of the same
length. Where two heating tubes are employed the clusters together form the
two legs or limbs of an inverted V beneath which is placed the furnace grate.
The construction of my boiler has for its object to produce a thoroughly
methodical circulation of the water and of the gases of combustion which allows
of obtaining a maximum capacity of vaporization and product; its size or bulk
is reduced to the minimum and its weight is much less than analogous boilers
capable of producing the same quantity of steam.
To this end each bundle or cluster of tubes is arranged in a novel way
whereby the methodical circulation of the water in the boiler and also of the
gases of combustion between the tubes is assisted. This arrangement consists
in dividing the tubes of each cluster longitudinally into two sets or layers by
a suitably perforated screen placed in the median plane of the said cluster in
the direction of the length of the heating tubes and in giving to the tubes placed
within the said screen at the side of the furnace a large diameter, in leaving
between them large free spaces for the combustion of the gases, whilst the tubes
placed outside the said screen, and nearer to the flue, have a small diameter
and are placed relatively very close together in order to receive the maximum
of heat from the gases.
Within the cylindrical body is arranged a circulation accelerator designed to
prevent stagnation and other causes of loss of power which may result, in the
cylindrical body itself, in the vicinity of the mingling ascending and descending
currents. To this end I construct the said circulation accelerator of partitions
of suitable shape, which completely separate the liquid currents; these partitions
form in the middle of the cylindrical body one or more chambers which receive
the whole of the mixture of water and steam rising through the large tubes
and discharge the said water laterally into the two adjacent chambers whence
it runs through the tubes of the outer clusters and returns to the heating tubes.
The walls of the furnace are of refractory material and the bodies of the
heating tubes, as well as that of the boiler, are covered with non conducting
composition on the parts exposed to the atmosphere.
The whole is contained in a sheet iron shell which forms a casing, constitutes
the ash box at the lower part, and is connected at the upper part to the lateral
flues for the escape of the gases, upon which the chimney is fixed.

page_text: In the accompanying drawing I have illustrated, as an example, a marine
water tube boiler having two heating tubes.
Figure 1 is a longitudinal vertical section; and
Figure 2 is a transverse section on the line 2-2 of Figure 1.
The horizontal cylindrical body a, or boiler proper, is arranged at the upper
part of the casing and the two heating tubes c and d are placed below the said
cylindrical body and at each side of the casing. Below the heating tubes the
furnace grate g, arranged longitudinally and occupying the whole width between
the upright supports g', gl of refractory material, separates the furnace, pro-
perly so called, from the ash box e.
Below the furnace doors ha metal plate is provided on to which the slag
from the coal which does not pass through the grate is drawn. It forms a hori-
zontal screen in front of the ash box and serves to support the ash box door
which can only open inwards and allows of having, if deemed necessary, and
without inconvenience, a slight excess of pressure in the ash box.
At the upper part of the casing and at the right and left of the boiler a are
fixed two flues which conduct the burnt gases to the chimney 1.
A cluster of straight tubes, inclined and of equal length, unite each of the
heating tubes c, d with the cylindrical body a; for this purpose the said heat-
ing tubes and cylindrical body are provided with flat portions forming tube
plates in which the tubes are fixed in the usual manner.
Each cluster of tubes is divided longitudinally into two sets or layers spread over
each side of the median plane passing through the axes of the cylindrical bodies
and corresponding heating tube. The tubes m placed within the said plane at
the side of the furnace have a relatively large diameter for resisting the action
of the fire; and wide passages are left between them for the combustion of the
gases, whilst the tubes n'placed outside the said plane and nearer to the flue
have a smaller diameter and are placed near one another in order to better
absorb the heat from the gases before they reach the flue.
Between the two sets of tubes m and n is arranged a metal screen or partition o
having suitable openings and which serves to direct the gases and cause them
to take the longest course around the clusters of tubes.
A second screen p, placed outside the tubes of small diameter n, forces the
gases which have passed through the clusters f and which, otherwise, would tend
to pass directly to the flue, to be turned back towards the heating tubes thereby
giving up the largest portion of their heat to the latter tubes n.
"
As clearly shewn in the drawing the boiler and the heating tubes are only in
direct contact with the furnace gases at the parts of their walls forming the tube
plates.
Upon the two inclined faces of the tube plate of the cylindrical body a parti-
tion in the form of an inverted trough, closed at its ends by vertical walls r',
is fixed, for example by means of angle pieces 2 which are arranged in the
space comprised between the two sets of tubes m and n.
The partition is surmounted by one or more chambers. In the drawing I
have shewn two chambers s, s, one in front and the other at the rear, and both
placed along the axis of the cylindrical body. These chambers are relatively
narrow but they occupy a large portion of the length of the boiler; they may
extend to any suitable height, but preferably rather higher than the maximum
level of the water in the boiler.
Above one or both of the chambers s, s a piece of sheet metal forming a
cap or hood is fixed by supports u attached either to the corresponding chamber
or to the side of the cylindrical body; it acts as a baffle to check the force of the
water and to prevent the water from being projected into the steam dome v.
The partition r surmounted by the chambers s forms in the cylindrical body a
central chamber into which open all the large tubes m, and two lateral chambers
connected with the outer tubes n.
The large tubes being heated to a temperature higher than that in the outer

page_text: clusters na considerable quantity of steam is produced therein, which by its
mixture with the water diminishes the density and causes in the said tubes m,
ascending currents which unite as they enter the cylindrical body and rise into
the chambers ss; the water discharged by these chambers falls laterally, at
the same time abandoning the steam which it brings along, and redescends to
the heating tubes c and d through the tubes n. In this circulation there is
never at any moment confusion or direct contact between the ascending and
descending currents and the result is that the speed of the water is very great
and brings the vaporizing capacity of the boiler and its capabilities to the
maximum.
I reserve to myself the right to vary, as required, the form, material and
dimensions of my boilers in their general arrangement as well as constitutive
parts, the number and the diameters of the tubes of the clusters, the relation
of the heating surface to the surface of the grate, the number and the arrange-
ment of the partitions interposed between the tubes of the clusters, and the
number and the form of the chambers constituting the circulation accelerator.
In conclusion I would remark that my boilers can be constructed with a single
heating tube or two heating tubes and that they are just as suitable for great
power as for medium or small power.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. A marine water tube boiler chiefly comprising a horizontal cylindrical body and
two heating tubes placed below the said cylindrical body, to which they are con-
nected by clusters of straight tubes, inclined and of the same length, each cluster
being divided longitudinally into two sets or layers spread over each side of the
median plane which passes through the axes of the cylindrical body and of the
corresponding heating tube, the tubes placed within this plane at the side of
the furnace having a large diameter and wide spaces between them for the
passage and free combustion of the gases, whilst the tubes placed outside the said
plane are of smaller diameter and are placed near one another, substantially as
set forth.
2. A marine water tube boiler comprising a cylindrical body and heating tubes
united by bundles or clusters of large tubes and small tubes as described in
the first claiming clause in combination with a circulation accelerator constructed
of a partition in the form of an inverted trough fixed upon the tube plate of the
cylindrical body and surmounted by one or more chambers and completely
separating the ascending currents issuing from the tubes which are situated
near the furnace from the descending currents directed towards the exterior
return tubes, substantially as set forth.
3. A marine water tube boiler comprising a cylindrical body a, two heating
tubes c and d, two clusters of tubes each divided into two sets of tubes of different
diameter m and n, in combination with partitions or screens o and p for directing
the gases of combustion and a partition or inverted trough r surmounted by
one or more chambers s for accelerating the circulation of the water, substan-
tially as herein before described with reference to the accompanying drawing.
Dated this 17th day of October 1899.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicant.