Improvements in Bollers.
Year: 1894

page_text: Date of Application, 16th Jan., 1894-Accepted, 10th Mar., 1894
COMPLETE DEMUIFICATION.
Improvements in Bollers.
I, LEON SERPOLLET, of 15 Rue des Halles, Paris, in the Republic of France,
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:-
The improvements which form the subject of this application have for their object
to increase the lightness and strength of the generating tubes, and also to make
their construction more precise, their inspection and replacement more easy, and
their durability greater.
The resistance to any deformation, as well as the lightness result principally from
the special shape A (Fig. 1) now given to the transverse section of the tube,
permitting the construction, without stays and without metallic laps, of tubular
groups formed of straight elements by means of which horizontal layers are formed
placed one above the other over the furnace and communicating together at their
extremities.
In Fig. 2 which is a longitudinal vertical section through the axis of the tubes
which are as may be seen placed one above the other to form a tubular group, and
in Fig. 3 which shows in plan a row of elements, the shape of one of these elements
will be noticed, it being here double or with two branches B B' but which could be
single or of more than two branches.
A neck C formed, in the forge, on the tube itself, connects the two branches B B₁
at the back. At the front ench is terminated by a tube piece D or D' also made
from the tube itself, and screwed at the end.
A connector D' serves to join and make communication between two neighbouring
elements so as to constitute a horizontal row.
Fig. 3 shows in plan, a row of a group or of a battery, of vaporising tubes
arranged in zig-zag (as shown in Fig. 6 which is part of a group looked at end-
ways) and in horizontal rows, one above the other over the furnace. As may be
judged from Figs. 2, 3 and 6, this multitubular group is fed in order to prevent the
destruction and deformation of the lower tubes which are those most exposed to
the action of the fire in the special manner hereafter described.
The water drawn up by the feed apparatus reaches by the tube piece E, Fig. 6
representing a portion of the front of the group, the first lower row passing
through all the branches thereof by means of the bends C at the back and the
connections D' at the front.
From this first row; and by means of the two way connection F provided with a
stop cock G the water may either pass to the second row or return wholly or in
part to the feed tank. In like manner if all the water supplied passes to the second
row it may also pass thence into the upper rows or return to the feed tank by the
two way connection F provided with the stop cock G¹.
By these means the boiler can be made to produce only the amount of steam
required by the engine and even to produce none at all if the motor is stopped
whilst maintaining the lower tubes sufficiently cool for them to keep their resisting
powers and to protect like screens, the upper tubes.
The bends C, the ends D D and the connections D' are protected from the
action of the flame and the gases of combustion, and at the same time the replace-
ment of the vaporising elements is facilitated by means of the arrangements
indicated by the Figs. 2, 3, 4, 5 and 6 which show respectively; the elevation with
vertical longitudinal section of a group of tubes; a horizontal section through this
group; a front view of the cast iron plate H which supports in front the

page_text: ends D D of the tubes; a front view of the cast iron plate I which supports at
the back, the bends C of the same tubes; and finally a front view of the group
provided with the movable plates N' and the stop bars P.
The plate H is provided with oblong openings J through which each of the
vaporising elements can pass. The back plate I is also provided with oblong
openings K supporting the bends C which can be easily disengaged. It is
strengthened by the ribs N.
The arrangements are designed to facilitate the removal and afterwards the
replacement of a damaged vaporising element or of a row without disturbing the
action of the rest of the boiler.
The back plate I (Fig. 5) is strengthened by the ribs N which form between
themselves and with the outer plate I. chambers filled with boiler covering or
siliceous mineral fibre.
The front plate H is also strengthened by ribs U forming between themselves
and with each of the movable and distinct plates N' spaces filled with fire resisting
material. Each of the plates N' which are supported by the crosspieces P is
removed at the time when one of the vaporising elements is to be taken out, and is
then replaced.
Fig. 7 shows the two parts of a mould between which is shown the transverse
section of the tube with an indication of its shape where joining with the part (
and the ends D D'.
Fig. 8 shows the longitudinal shape of this tube.
These two figures enable the processes to be understood by means of which these
shapes of the new vaporising tubes are obtained in a precise manner.
It is from the cylindrical metallic tube Q shown in Fig. 8 and which it is
supposed has been chosen of the required dimensions, that the vaporising
element B B¹ is obtained. The middle part which is to form the neck C is forged
smaller as are also the ends which form the tube pieces D D' and which have to be
screwed before the tube is bent. After this the tube is placed whilst hot between
the two parts R R' of the mould O.
The original cylindrical part of the tube Q except at the points S S¹ is subjected
to the pressure and brought to the transverse shape A and the longitudinal
shape A shown by Fig. 1 and Fig. 8, having inside an appreciable capillary
space a in the shape of a crescent. This space is slightly and progressively
increased proportionately as the vaporising tube belongs to a higher row and as it
approaches the outlet piece F³ (Fig. 6). The object of this is to give the steam in
proportion to its production a less restricted passage whilst still keeping it small.
To obtain this result stops T are inserted between the parts R R of the mould O,
the thickness of which is increased in proportion to the position of the vaporising
tubes produced being in higher rows.
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 :-
In multitubular instantaneous vaporisation boilers-
•
1. The novel vaporising tube formed of two elements B B₁ connected by the
tube space C terminated by the extremities D D' this tube space and these
extremities, forged smallar axially being connected to the rest of tube by the
cylindrical parts S S'; the said vaporising tube having a transverse section of
the shape A with an interior space a appreciably capillary and also in the form
of a crescent, which space increases in height towards the centre in proportion as
the vaporising element is intended to be placed further from the point at which the
feed water reaches the tubular group, substantially as described.
2. The combination of the vaporising element thus formed, with other similar
elements, by means of the connections E, D, F, G, F¹, G¹, F³, in such manner as
to obtain rows of tubes arranged in zig-zag, forming a tubular group fed from the
bottom upwards from one tube to the other, the injected water being either entirely

page_text: transformed into steam and sent to the motor cylinder, or with the object of only
cooling the lower tubes, being returned to the feed tank wholly or in part by the
two way connecting piece F provided with the stop cock G or by the connecting
piece F also with two ways and provided with the stop cock G, substantially as
described.
3. The combination of the tubular group, thus arranged and fed, with the two
supporting plates H and I at the front and back, provided respectively with the
openings J, K, strengthened respectively with the ribs U, N, forming between
themselves and with the exterior cover plate L and the movable and distinct
plates N supported by the cross pieces P spaces which are filled with boiler
covering or siliceous fibre, the whole with the object of facilitating the replacement
of the vaporising tubes and preventing the dispersion of the heat of the furnace,
substantially as described.
4. The methods and processes applied to the preparation and completion of the
vaporising tubes B B' and consisting of making smaller the middle and ends of the
original tube Q and then bringing it to the traverse and longitudinal_shapes
shown in Figs. 1, 7, and 8 by pressing it whilst hot between the two parts R R₁ of
the mould O, the variation of the height at the centre of the capillary space a in
the shape of a crescent being obtained by the interposition between Ŕ and R' of
stops T of variable thickness substantially as described.
5. The improvements in boilers substantially as described and shown on the
drawings hereunto annexed.
Dated this 16th day of January 1894.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.