Improvements in Water-tube Steam Generators
Year: 1896

page_text: Date of Application, 18th Dec., 1896
PROVISIONAL SPECIFICATION.
"Improvements in Water-tube Steam Generators."
I, JAMES HERMANN ROSENTHAL, of 147 Queen Victoria Street, in the City of
London, Engineer, do hereby declare the nature of this Invention to be as
follows:-
This Invention has for its object to provide a vertical boiler of the water tube
type and of improved construction for use mainly in launches or small steamers,
in steam tramway locomotives, portable cranes, motor cars and the like, and gener-
ally where comparatively small power and light weight only is required.
The improved boiler comprises a steam and water drum composed of a short
vertical cylinder having dished or domed top and bottom ends riveted or bolted to
it. This drum is suspended by angle iron rings or otherwise within the upper end
of a tapering vertical casing enclosing a furnace or combustion chamber the firegrate
of which is placed centrally in the lower end of the casing which sits on a base
piece enclosing an ash space or forming an ash box. In the lower end of the
drum several rows of water tubes are expanded or secured by means of screw bushes
and depend in tapered ring form within the combustion chamber towards the lower
end of the casing and so as to surround the fire grate or an annular bridge of
firebrick or like refractory material enclosing the grate. Suitable baffle plates
are provided to direct the fire gases, which first play on the inner rows of tubes,
down over the bridge and thence upwards among the outer rows of tubes on their
way towards the chimney outlet which is formed in the upper end of the outer
casing.
The water tubes are by preference of the "Field" type or of similar type having
their lower ends closed either permanently or by means of removable caps provided
for cleaning or for emptying, and having smaller open ended tubes fitted within
them, the smaller tubes having their lower ends terminated short of the closed
ends of the surrounding larger tubes and being held centrally therein by flaring
tongues out from the tubes or by other means, whilst the upper ends of the inner
tubes are carried up beyond the ends of the outer tubes and have their ends secured
in a tube plate made in the form of a tray into which the feed water is directed
so that circulation takes place by descent of the cooler water through the inner
tubes to their lower ends and ascent through the outer tubes exposed to the heat
of the fire gases, the heated water and steam generated passing upwards into the
drum. The lower end of the drum is dented or pressed upwards at the middle to
strengthen it and at the same time afford a support for the tray to which the
inner tubes are secured, whilst around the central dent the drum end is flattened
to receive the ends of the rows of outer tubes at about right angles to its surface.
Within the steam space of the drum and over the inner tube plate the feed inlet
is or may be terminated in a spray nozzle or rose which directs the feed water in
the form of spray into a tray wherein impurities in the water may be collected

page_text: and periodically blown off, or removed with the tray through a manhole opening
in the upper end of the drum.
The feed water may be heated by passing it through a coil of piping fitted
in the upper part of the combustion chamber and encircling the water tubes or
lower end of the drum.
The base piece of the boiler casing is made in the form of an annular trough
provided with a drain cock for convenience of withdrawing the water when
removing the tube caps to empty the boiler.
The furnace may be formed by a circular fire grate enclosed by an annular or
horse shoe form of bridge wall as above mentioned, to which access is obtained
by a firing door in the side of the casing, the tube at that point being correspondingly
shortened; or when oil or gaseous fuel is used the fire grate may be replaced by
a central well of fine clay or like refractory material into which the stream of
fuel may be directed from the bottom or side.
Dated this 17th day of December 1896
WALLACE
FAIRWEATHER
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62 Saint Vincent Street, Glasgow.
Agent for the Applicant.
I, JAMES HERMANN ROSENTHAL, of 147 Queen Victoria Street, in the City of
London, 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:-
This Invention has for its object to provide a vertical boiler of the water tube
type and of improved construction for use mainly in launches or small steamers,
in steam tramway locomotives, portable cranes, motor cars and the like, and
generally where comparatively small power and light weight only is required.
The Invention is illustrated by the accompanying drawings, Fig. 1 being a
vertical section, and Fig. 2 a horizontal section on the line - Fig. 1, of
my improved water tube generator in which coal or other solid fuel is used; and
Fig. is a vertical section, Fig. 4 a horizontal section of a modification on the
line yy, and Fig. 5 a vertical elevation in which liquid or gaseous fuel is used.
Figs. 6 and 7, are enlarged views of one of the water tubes used in the steam
generator.
The improved boiler comprises a steam and water drum A composed of a short
vertical cylinder having dished or domed top and bottom ends A', A³, riveted
or bolted to it. This drum A is suspended by angle iron rings B or otherwise
within a vertical casing C enclosing a furnace or combustion chamber 1) the
firegrate of which is placed centrally in the lower end of the casing
C which sits on a base piece F enclosing an ash space G or forming an ash box.
In the lower end of the drum A several rows of water tubes H are expanded or
secured by means of screw bushes and depend in tapered ring form within the
combustion chamber D towards the lower end of the casing C and so as to
surround the fire grate E or an annular bridge I of firebrick or like refractory

page_text: material enclosing the grate E. Suitable baffle plates such as J, K, are provided
to direct the fire gases, which first play on the inner rows of tubes H, down over
the bridge I and thence upwards among the outer rows of tubes H on their way
towards the chimney outlet K which is formed in the upper end of the outer
easing.
The water tubes H are by preference of the "Field" type or of similar type
having their lower ends closed either permanently or by means of removable
caps H provided for cleaning or for emptying, and having smaller open ended
tubes H fitted within them, the smaller tubes H3 having their lower ends
terminated short of the closed ends of the surrounding larger tulies H and being
held centrally therein by flaring tongues H cut from the tubes or by other
means, whilst the upper ends of the inner tubes are carried up beyond the
ends of the outer tubes H and have their ends secured in a tube plate made in
the form of a tray L into which the feed water is directed so that circulation
takes place by descent of the cooler water through the inner tubes H2 to their
lower ends and ascent through the outer tubes H exposed to the heat of the fire
gases, the heated water and steam generated passing upward into the drum
A. The lower end A2 of the drum A is dented or pressed upwards at the middle
to strengthen it and at the same time afford a support for the tray L to which the
inner tubes H are secured, whilst around the central dent the drum end A³ is
flattened to receive the ends of the rows of outer tubes H at about right angles
to its surface. Within the steam space of the drum A and over the inner tube
plate or tray L the feed inlet M is or may be terminated in a spray nozzle or
rose N which directs the feed water in the form of spray into a tray O wherein
impurities in the water may be collected and periodically blown off or removed
with the tray through a manhole opening A3 in the upper end A of the
drum A.
The feed water may be heated by passing it through a coil of piping P fitted in
the upper part of the combustion chamber D and encircling the water tubes Hor
lower end of the drum A.
The base piece F of the boiler easing is made in the form of an annular trough
Qas shown at Figures 1 and 2 and provided with a drain cock R for convenience
of withdrawing the water when removing the tube caps I to empty the
boiler.
The furnace may be formed by a circular fire grate enclosed by an annular
or horse shoe form of bridge wall as above mentioned, to which access is obtained
by a firing door in the side of the casing, the tubes at that point being corres-
pondingly shortened; or when oil or gaseous fuel is used, as in the modification
illustrated by figures 34 and 5, the fire grate may he replaced by a central well
S of fire clay or like refractory material into which the stream of fuel may be
directed from the bottom or side:
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:
1. A vertical water tube steam generator composed of a short vertical drums
fitted within a cylindrical or tapering casing enclosing a furnace and having
secured to its under dished end a row or rows of depending double tubes of the
"Field" or similar type the inner tubes of which are carried up and secured to
a separated tube plate or tray within the drum so that circulation is ensured
by descent of the cooler water through the inner tubes and its ascent through
the outer tubes exposed to the fire gases substantially as described.
2. The improved water tube steam generator constructed and arranged sub-
stantially as described with reference to figures 1 and 2 of the accompanying
drawings.
3. The improved water tube steam generator constructed and arranged sub-

page_text: stantially as described with reference to figures 3, 4, and 5 of the accompanying
drawings.
Dated this 18th. day of Sentember 1897.
WALLACE FAIRWEATHER
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents.
62 Saint Vincent Street, Glasgow.
Agent for the Applicant.