Improvements in Tubes for Instantaneous Steam Generators.
Year: 1897

page_text: Date of Application, 21st May, 1897-Accepted, 17th July, 1897
COMPLETE SPECIFICATION.
Improvements in Tubes for Instantaneous Steam Generators.
We, LA SOCIÉTÉ DES GÉNÉRATEURS À VAPORISATION INSTANTANÉE SYSTÈME
L. SERPOLLET, and LEON SERPOLLET, both of 15 Rue des Halles, Paris, France,
Engineers, 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 improvements in the construction of vaporizing tubes
of quasi-capillary internal section and intended to constitute an instantaneous
steam generator or part of such a generator and it has for object and for result
to render such vaporizing tubes stronger whilst very much lighter than usual and
at the same time to render their manufacture more simple and their shape more
regular and more suitable for utilizing the action of the heat given off by the
furnace, irrespective of the nature of the said furnace, that is to say whatever may
be the system of heating employed, and irrespective of the regularity or the
intermittency of the heating. The improvements consist after having obtained
a flat tube of the desired length and section, the said section being of the plane
shape indicated at A in Fig. 1 of the accompanying drawings, in filling the said
tube with dry fine sand, and then, whilst the sand is confined, in twisting the said
tube about its longitudinal axis as shown at B, in such a manner that the ends of
the plane section forming the longitudinal edges of the tube, shall assume the
form and direction of two parallel helices of greater or less pitch, as shown in
Fig. 2. This figure shows a short length of the new tube ending at one side of the
figure in a screw threaded tubular union piece C for engagement with a union nut,
the oblique section taken from the opposite side, showing that the helical
arrangement will also be assumed by the approximately capillary internal space.
The tube thus formed by longitudinal torsion, may be left straight, or it may
be coiled in the form of a spiral arranged in a single plane, or it may be coiled to
form two or more spirals or stages" wound in the same direction, arranged side
by side and connected at the centre, as shown in front and side elevation in
Figs. 3 and 4 respectively, or it may be bent in zig-zag fashion into the form of a
flat serpentine coil of several convolutions or branches as shown in front eleva-
tion in Fig. 5 each end terminating in a flanged union, or, as shown in the said
figure in a screw threaded union similar to that shown in Fig. 2 and suitable
for engagement with a union nut E; the two unions, one for the entrance of the
water or steam, and the other for the exit thereof, being situated on the same side
as shown in full lines in Fig. 5, or one on one side and the other on the opposite
side, as shown in full and dotted lines, or at another place.
Several tubes coiled in a spiral manner, or bent into the shape of flat serpentine
coils, may be arranged above one another, or coupled together side by side, in such a
manner as to form series of tubes arranged in stages, or coupled together in suffi-
cient number to allow of the whole of the generator exposing the necessary heating
surface to the furnace gases. These several tubes are jointed or connected together,
or to collecting tubes, either by end unions, or by connecting bends which may
Pain Q.71

page_text: be simply cylindrical, or may themselves be twisted helically, or by simple tubular
union pieces.
In the spiral arrangement, when the two end portions D D' of the tube, one for
the inlet and the other for the outlet, are placed side by side, they are or may be
connected together by a collar F, whereby all deformation caused by the pressure
which the steam may acquire inside the tube, is rendered impossible. The said end
portions of the tube may be twisted like the remainder of the tube, or be left
cylindrical as shown.
The great resistance offered to the internal pressure of the steam by the new form of
the vaporizing tube, allows of making the tube with very thin walls so as to pro-
duce a light vaporizing apparatus, whilst rendering it at the same time suitable
for all intermittent heating, of suitable intensity, especially for heating effected
by means of burners fed with petroleum or any other combustible liquid.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
1. A tube having two longitudinal edges or projections with an approximately
capillary internal space, twisted into helical form, as herein before described and
shown for the purpose specified, the said twisted tube being left either straight, or
coiled into a spiral form, or bent into a flat serpentine form.
2. The method of constructing the tube referred to in the preceding claim by
filling a flattened tube with dry powdered sand, twisting the tube whilst the sand
is confined therein, and discharging the sand after a sufficient twist has been
imparted to the tube, as set forth.
3. The improved tubes of approximately capillary internal section and with
coupling unions, herein before described with reference respectively to and shown
in Fig. 2 in Fig. 3; and in Fig. 4 of the drawings annexed.
Doted this Olot of X 1007
F. WISE HOWORTH.
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.