Improvements in or relating to Water-tube Steam Generators.
Year: 1898

page_text: Date of Application, 26th Mar., 1898-Accepted, 18th Feb., 1899
COMPLETE SPECIFICATION.
Improvements in or relating to Water-tube Steam Generators.
I, PAOLO MARTINELLI, Managing Director of the Societe pour l'Explostation
de Couvertes Industrielles, Naples, in the Kingdom of Italy, 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 tubular steam generators in which
the tubes are inclined at an angle, to which are attached at right angles tubes of
square or rectangular cross section, these latter being connected with each other
by a number of other tubes.
"The invention is illustrated in the accompanying drawing in which Figures A B C
are respectively a front, and side elevation partly in section and plan view,
Figures A and B' showing a modified construction in front and partial side eleva-
tion. The generators in Figures A and B show 8 tubes converging towards the
top and provided in all with 44 transverse tubes connected by longitudinal tubes
inclined downwards towards the back.
The generator shown in Figure C has two cylindrical reservoirs and a conical
central collector connected to the former by branches.
In the generator shown in Figures A and B¹ there are 4 substantially vertical
tubes of rectangular, instead of circular cross section and there are no cylindrical
reservoirs the tubes being directly connected to the central collector. The trans-
verse tubes are also of square cross section and are connected by longitudinal tubes
having a smaller inclination than in the generators first described.
The new steam generator consists chiefly of a number of more or less inclined
tubes d of any desired cross-section to which are secured at right angles transverse
tubes f of square or rectangular cross section inner ends of which are free and
closed, and which are connected with each other by a number of longitudinal
tubes g.
The steam generator is constituted by a number of tubes d arranged at its four
corners and of a given size and of any desired cross section i.e., circular, oval
square etc. which tubes are slightly inclined relatively to the bottom of the genera-
tor.
These tubes (which may be provided at the top with valves e adapted to close
them for the purpose to be hereinafter described) carry secured to them at a right
angle or slightly inclined other straight tubes f smaller than the vertical tubes
and of square or rectangular cross-section the inner ends of said transverse tubes
being closed and free to expand. A number of straight tubes g smaller than the
transverse tubes f of circular cross-section and perceptibly inclined relatively to
the bottom of the generator, connect the transverse tubes in front with those
situated at the back of the steam generator. In this way all the upwardly ex-
tending and all the transverse tubes on the same side, connected by the longitudinal
tubes, form a communicating system on one side of the generator another system
being formed on the other side of the generator. These two systems are connected
together and thus form one whole, either by each system being provided at the top
with a cylindrical longitudinally reservoir of a size which must be of larger

page_text: capacity than all the tubes already mentioned, said reservoir being also arranged
at an angle to the bottom of the generator. Each reservoir forms a communicating
connection between the tubes on each side. The two reservoirs are connected by
short pipes to a larger reservoir in the centre constituted by a conical tube
placed between the two cylindrical reservoirs, the upper side of the conical reser-
voir being parallel to the bottom of the generator and the lower one being at the
same angle and nearly level with the cylindrical reservoirs.
Or the upwardly extending tubes are connected directly to the central collector
by short bends j' as shown in Figure A¹.
Under the longitudinal tubes g there is a suitable space and at the bottom of it
there is arranged the usual grate, a combustion chamber and an ash pit being thus
formed. The combustion chamber may be divided by a light partition of refractory
bricks arranged longitudinally in the centre of the generator and extending in
height from the bottom of the generator to the bottom of the central collector, thus
producing two separate combustion chambers in which two separate fires can be
lighted. Of course in this case there must be two grates."
When the combustion chamber is thus divided so as to render the two halves
of the steam generator independent of each other in case of damage in order to
enable the repairs to be done in the damaged half without interrupting the working
of the half in good order, the tubes of the damaged set will be closed by means of
the valves e. The bottom face and the two sides of the generator are closed by sheet
metal doors lined inside with refractory material. At the top the generator is covered
by a lined sheet metal arch o provided with an opening for the chimney p. The
generator is of course provided with all the usual necessary fittings, such as feed,
and safety valves, drain-cocks, water levels, etc. The sizes the inclination and
the number of the tubes depend on the power it has to develop and on the use for
which it is destined. The generator should be filled with water until the level
reaches one third of the height of the central collector. The flame heats at first
the water in the small longitudinal tubes g, which water begins to evaporate, the
steam formed passing forward into the transverse tubes f and thence into the front
tubes d. From these it passes in a continuous manner into the top cylindrical
reservoirs h, if there be any, and from them into the central collector whence it
is taken and supplied for any purpose required. The water in the generator
constantly renewed by feed pumps flows continuously into the tubes d at the back
and from those into the transverse tubes f connected to them and thence into the
longitudinal tubes 9 where it thus arrives already slightly heated and is quickly
converted into steam, and so on.
The advantages of the steam generator according to this invention are as
follows: Maximum utilisation of heat, quick and perfect circulation of water,
ample production of very dry steam small amount of space required relatively to
the power developed, the weight of the apparatus being only about half that of
other generators of the same power, no danger of explosion, absolute safety, great
strength enabling the pressure to be safely raised to a higher value than has
been hitherto possible, facility of replacing broken tubes, the advantage of having
one half of the generator working, even when the other half is being repaired and
finally the freedom of expansion in all the parts.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I
claim is
1. A tubular steam generator comprising a series of upwardly extending tubes
inclined towards the centre of the generator and having secured to them transverse
tubes of square or rectangular cross-section, the inner ends of which are free and
closed, said transverse tubes in front of the generator being connected to those
at the back by longitudinal tubes inclined relatively to the bottom of the generator
substantially as described.
2. A tubular steam generator divided into two parts either of which can be cut

page_text: off from the main collector each half comprising one or more upwardly extending
tubes at the front and back of the generator to which are attached transverse
inwardly extending tubes having their inner ends free and closed, said tubes at
front and back being connected together by a series of longitudinal tubes, the
upwardly extending tubes being connected either directly to the steam collector
or to tubes communicating therewith substantially as described.
3. The combination and arrangement of parts constituting the complete tubular
steam generator substantially as described or illustrated in Figures A, B and C or
in Figures A and B₁ of the accompanying drawings.
Dated this 26th day of March 1898.
BOULT & WADE,
Agents for the Applicant.