Improvements in Steam Generators.
Year: 1899

page_text: Date of Application, 29th Apr., 1899-Accepted, 22nd July, 1899
COMPLETE SPECIFICATION.
Improvements in Steam Generators.
We, THE OTTENSENER EISENWERK (vormals Pommée and Ahrens), of Altona
Ottensen, Germany, and HERMANN ROSENTHAL, of Treskowstrasse 13, Hamburg,
Germany, Engineer, do hereby declare the nature of this invention, and in what
imanner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
Up to the present water-tube steam-generators have alone been regarded as
practicable where high-pressures are concerned whilst fire-tube boilers are only used
for pressures of, at most, 15 atmospheres, and generally-speaking occupy, for the
same heating surface, a considerably greater space than water-tube steam generators.
On the other hand the evaporative-power of the latter type of steam generators per
unit of heating surface is, according to experience, considerably lower than in
the case of fire-tube boilers and consequently the heat-utilisation is often
insufficient.
According to this invention the advantages of both systems are united and a steam
generator is obtained which is adapted for as high a pressure as may be desired and
which occupies the smallest possible space and has the highest evaporative power.
A generator according to the present invention is represented in the accompanying
sheet of drawings in a form more especially adapted for marine use
Figs. 1 and 2 being cross sections at right angles to one another.
Fig. 3 a front elevation,
Fig. 4 a horizontal section,
Fig. 5 a plan, and Fig. 6 a side elevation.
Over the grate a are two steam-generating elements and c inclined towards one
another.
Each of these forms a separate receiver and is bounded by two flat tube-walls and
by two arched walls, so that the vessel is shaped like a flat cushion.
In the parallel
tube-walls of each element as large a number as possible of heating or fire tubes &
of small diameter, so-called dwarf-tubes, are screwed or otherwise fastened so as to
be steam-tight and water-tight. Inside the elements these tubes are covered with
water, the level of which rises above the whole system of tubes to a certain height.
Above the surface of the water there is, as in other steam generators, the so-called
steam space.
Whilst the flat walls can be sufficiently braced in the water-space by the heating
tubes themselves, the same are suitably stiffened in the steam space by braces f.
The furnace-gases rising from the grate a flow through the heating-tubes d to a
smoke-chainber g and thence on to the chimney. In the arrangement shewn the
heating elements b-c bound the fire-space behind and in front. "Above and at the
sides the same is bound by masonry h.
The stoking is effected by means of fire-doors i and the lower air-delivery is regu-
lated, as desired, by dampers i¹.
Each element forms a separately-working steam generator and can, therefore, be
used by itself. When several elements are united the separate water or steam spaces
can be connected by pipes, on which are placed the usual fittings such as water-
gauges, safety valves and so on (as shewn in Figs. 3,
and 6).

page_text: The construction described affords a reliable internal bracing of the elements band c
for the highest pressures and the arrangement of the heating-tubes brings about a
substantial increase in the evaporation.
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
clain is-
1. A steam-generator comprising one or more box-like elements b c inclined to the
grate a, each element having two sides forming parallel tube-walls in which are fitted
a number of small fire tube d having a straight passage for the furnace-gases sub-
stantially as described.
2. The improved steam generator combined and arranged substantially as described
and shown in the accompanying drawings.
Dated this 00LL
SA 1000
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.