Improvements in Steam Generators.
Year: 1898

page_text: Date of Application, 20th Dec., 1898-Accepted, 13th May, 1899
COMPLETE SPECIFICATION.
Improvements in Steam Generators.
I, VALENTIN PURREY, of 97, Rue St. Lazare, Paris, in the Republic of France,
Mechanical 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:
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This invention relates to a multitubular steam generator and is illustrated in
the accompanying drawings in which:-
-¡
Figure 1 is an elevation of my improved apparatus partly in section on the
line A. B. Figure 2.
Figure 2 is a cross-section on the line E F of Figure 1.
Figure 3 is an end elevation.
Figure 4 shows the connection of the upper extremities of the pipes to the
collector or drum.
Figures 5 and 6 show the connection of the lower extremities of the pipes to
the feed collector and
Figures 7 and 8 show a modification.
The improved generator is composed of bent tubes a a communicating at their
upper extremities with a steam collector or drum b, and at their lower extremities
with a feed collector c.
These collectors are connected by two water return pipes d d. The lower
portion of the tubes a is surrounded by a metal or asbestos protecting sheath or
casing e.
The whole is arranged within a sheet metal casing f and placed above a furnace
having an inclined grate g. A screen h (Figure 2) prevents the water return
pipes from being directly in contact with the combustion gases.
If the steam produced by the generator is to be superheated, I may (as repre-
sented in Figures 7 and 8) cause the lower extremities of a certain (variable)
number of bent tubes a¹ issuing from the steam chamber or drum to terminate in
a collector for superheated steam, which is independent of the feed collector
and not in .communication with it. In this manner, all the steam produced in
the generator is compelled to circulate in the tubes a', where it is superheated
by direct contact of these tubes with the furnace flames, and collects in the
collector c from which it is conducted by the steam pipe V to the apparatus
in which it is to be utilised. The steam collector b in this case, need only be
provided with a single pipe S upon which is mounted a safety valve.
Each of the tubes is fixed in the following manner: It is formed at its
extremity (Figures 4 and 5) with a reduced portion which is engaged in a hole,
bored in the wall to which the tube is to be fitted and then cupped by the intro-
duction with force of a mandrel through an opposite aperture which is then
closed by means of a screw plug i.
The furnace is charged by means of a hopper j (Figures 1 and 3). The
furnace door is arranged opposite to this hopper.
The generator also comprises a feed regulator and a draught regulator.

page_text: The feed regulator (Figures 1 and 2) consists of a float m displaceable around a
shaft n which it causes to participate in its movement. One of the extremities
of this shaft is provided with an arm o attached by means of a connecting rod P
to the plug of a cock q inserted upon a feed pipe s termining in the supply trough.
When the water is at its normal level in the collector 6 the cock q is completely
closed, and the water forced into the pipe s by the feed pump litts the valve t
and enters the feed collector c. If the level of the water rises excessively, the
float m also rises and by means of the arm o and connecting rod p gradually
opens the cock q. A portion of the feed water then returns to the supply trough
until the normal level is again reached. At this moment the float will have
again closed the cock and all the feed water enters the boiler.
The draught-regulator (Figures 1 and 3) consists of a fixed cylinder u in com-
munication by means of a pipe v with the steam chamber of the collector b. Within
the cylinder u is displaced a piston w, connected by means of a connecting rodz
with a lever mounted upon the axis of the ash-pit door. With the rod is dis-
placed a stirrup-shaped part y acted upon in an upward direction by a spring z.
If the pressure exceeds the normal value for which the spring z has been adjusted,
the piston w falls and closes the ash pit door. When the pressure diminishes the
spring z displacing the stirrup y causes the piston w to rise and throws the ash-
pit door wide open.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. A steam generator consisting of bent tubes a a which communicate by their
upper extremities with a steam collector 6 and by their lower extremities with a
feed collector c, the two collectors b and c being placed in communication by
two water return pipes d d, the lower portion of the tubes a which is directly
exposed to the flames of the furnace being surrounded by a protecting sheath e
of metal or asbestos.
2. A steam generator characterised in the preceding claim and in which a
certain (variable) number of bent tubes at issue from the steam chamber band
terminate in a collector e for superheated steam which is independent of the
feed collector c and does not communicate therewith, the said steam collector c¹
being provided with a superheated steam supply pipe V.
3. The method of fixing the tubes a, consisting in reducing the extremity of the
tube and cupping it in an aperture in the wall by means of a mandrel introduced
through an aperture which is subsequently closed by means of a screw plug.
which is
4. A feed regulator, consisting of a float m operating a shaft n provided with an
arm o attached by means of a connecting rod p to the plug of a cock
inserted upon a piper branching out of the feed pipe a.
5. A draught regulator, consisting of a fixed cylinder u, in communication by
means of a pipe with the steam chamber of the collector 6 and within which is
displaced a piston w the rod of which is connected by means of a connecting rod x
with a lever mounted upon the axis of the ash-pit door k, and displaces a stirrup y
acted upon by a spring z of variable tension.
6. The combination in one and the same apparatus of the parts and devices above
claimed.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.