Improvements in Steam Generators.
Year: 1897

page_text: Date of Application, 31st Mar., 1897
Complete Specification Left, 2nd June, 1897-Accepted, 3rd July, 1897
Improvements in Steam Generators.
We, THE STEAM CARRIAGE & WAGON COMPANY, LIMITED, and JOHN EDWARD
THORNYCROFT, both of Homefield, Chiswick, in the County of Middlesex, Auto-car
Builders do hereby declare the nature of this invention to be as follows:-
This invention has reference to improvements in steam generators, the object
being to produce a light, compact and efficient steam generator such as may be
advantageously employed in motor propelled vehicles or for other purposes.
A generator according thereto comprises upper and lower annular chambers
connected by water tubes arranged to form walls of a fire box adapted to be supplied
with fuel through an opening bounded by the upper annular chamber, which
opening is furnished with a suitable fire door, and a fire grate being located with
its upper surface above the lower annular chamber below which there is a casing
or chamber furnished with a removable ash pan; the flame and products of com-
bustion from the burning fuel on the grate ascend within the fire box, then
proceed laterally through openings left for the purpose between the upper portions
of the water tubes of the inner row, then descend between the inner and outer
rows of tubes and pass out through spaces left for the purpose between the lower
portions of the water tubes of the outer row and thence into a space between the
outer row of tubes and an external casing which is or may be in communication
with the chamber of an exhausting fan whereby the gaseous products are caused
to pass it may be into an uptake or it may be into a funnel or passage leading
either to the external atmosphere or elsewhere.
The lower side of the upper annular chamber and the upper side of the lower
annular chamber constitute tube plates and the alternate tubes of each row are
bent so that their respective ends are at a greater distance radially from the vertical
axis of the fire box than the corresponding ends of the tubes juxtaposed to them.
This arrangement obviates excessive weakening of the tube plates by forming the
holes therethrough unduly close to one another; it also provides the openings,
where necessary, for the passage of the hot gases between the tubes. Where the
gases are not to pass through openings formed in the manner described, rings
are provided which form closures to the openings in question.
In combination with the upper annular chamber there may be provided a
steam dome and separator comprising a vertical steam pipe that is in communica-
tion with the steain space of the annular chamber and has arranged centrally
within it a small open-ended pipe, the lower end of which is below the level of
the water in the upper annular chamber. This small pipe is perforated at
intervals of its length and has attached to it a corresponding number of separating
devices each comprising a lower funnel or cup shaped part of less diameter than
the steam pipe and adapted to conduct any water Howing into it towards one of
the perforated parts of the central pipe and an upper truncated cone-shaped part
the upper edge of which is in contact with the wall of the steam pipe and the
lower edge of which is somewhat above and of less diameter than the upper eage
of the lower part; the upper part is supported on the lower by legs preferably so

page_text: formed as to form guides down which the water flows. With this arrangement
the steam and water is deflected by the lower part of each separating device
against the wall of the steam pipe and the back or outside of the upper part, the
steam passing under the lower edge of the latter, whilst the separated water flows
down the back of the upper part into the lower part, whence it passes through
the perforations into the central pipe back to the water space of the upper annular
chamber. For use on a vehicle the generator is preferably provided with a
separator of this kind of considerable height.
Referring to the accompanying illustrative drawings,
Fig. 1 shows in central vertical section a steam generator according to this
invention.
Fig. 2 shows a plan of the generator, partly in section.
Figs. 3 and 4 are a vertical section and a plan respectively of a steam dome and
separator according to this invention and Fig. 5 is a developed face view of the
upper part thereof.
The upper annular steam and water chamber is represented as being constructed
of two main parts namely an annular part 1 of U section with outward flanges 2
which may be of cast metal or may be of pressed steel and an annular tube plate 3
to which the part 1 is connected by bolts 4 passing through its flanges. 5 is the
opening through which fuel is fed and 6 the fire door.
The lower annular water chamber resembles the upper annular chamber but is
much shallower and comprises an annular part 7 of U or channel section with
flanges 8 and an annular tube plate 9, these being secured together by bolts 10.
The upper and lower annular chambers are connected by water tubes 11 and 1g,
the construction and arrangement of which will be understood from the description
already given aided by reference to the drawings.
In the example, the tubes 11 constitute the inner row and the tubes 12 the outer
rów but there might be more rows. 13 is the fire grate and 14 the chamber or
casing below it; 15 is the movable ash pan. 16 is the outer casing of the generator;
17 the fan casing; 18 the fan, whose blades are or may be as represented straight
and radial so as to have an exhausting action whether driven backwards or for-
wards. 19 is the funnel which may be connected to the fan casing as represented
in full lines in Fig. 1, or the fan may discharge the products of combustion down-
wardly into a passage or flue as indicated by dotted lines. The course of the
products of combustion is indicated by arrows. 20 is a ring arranged opposite
to those portions of the tubes of a row between which there are openings through
which the passage of hot gases is to be prevented. In the case of a boiler with
more than two rows of tubes other rings 20 would be provided where necessary. 21
is a baffle plate for preventing the flame coming directly into contact with the
tube plate 3.
22 is the steam pipe forming a steam dome and containing a central open-ended
pipe 23 (see Figs. 3 and 4) perforated at 23 to which are attached separating
devices each comprising a lower part 24 and an upper part 25, that is formed with
legs 25 and has the portions of its lower edge that are between the legs suitably
curved (see Fig. 5) for the purpose of causing the separated water to flow towards
and down the said legs, thereby leaving a free passage for the separated steam and
obviating liability of the steam and water becoming again mixed. The legs 25*
may, if desired, be formed with external grooves which serve as channels for
the water.
The fire bars may with advantage be rivetted together in separate groups so
that when it is necessary to clean the fire, the central group can be removed, by
pulling it out with a firing tool, and the clinkered fire be pushed through the
opening thus formed in the grate and allowed to fall into the ash pan.
'
Dated this 31st day of March. 1897.

page_text: We, THE STEAM CARRIAGE & WAGON COMPANY, LIMITED, and JOHN EDWARD
THORNYCROFT, both of Homefield, Chiswick, in the County of Middlesex, Auto-car
Builders, 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 reference to improvements in steam generators, the object
being to produce a light, compact and efficient steam generator such as may be
advantageously employed in motor propelled vehicles or for other purposes.
A generator according thereto comprises upper and lower annular chambers
connected by water tubes arranged to form walls of a fire box adapted to be supplied
with fuel through an opening bounded by the upper annular chamber, which
opening is furnished with a suitable fire door, and a fire grate being located with
its upper surface above the lower annular chamber below which there is a casing
or chamber furnished with a removable ash pan; the flame and products of com-
bustion from the burning fuel on the grate ascend within the fire box, then proceed
laterally through openings left for the purpose between the upper portions of the
water tubes of the inner row, then descend between the inner and outer rows of
tubes and pass out through spaces left for the purpose between the lower portions
of the water tubes of the outer row and thence into a space between the outer row
of tubes, and an external casing which is or may be in communication, with the
chamber of an exhausting fan whereby the gaseous products are caused to pass it
may be into an uptake or it may be into a funnel or passage leading either to the
external atmosphere or elsewhere.
The lower side of the upper annular chamber and the upper side of the lower
annular chamber constitute tube plates and the alternate tubes of each row are
bent so that their respective ends are at a greater distance radially from the vertical
axis of the fire box than the corresponding ends of the tubes juxtaposed to them.
This arrangement obviates excessive weakening of the tube plates by forming the
holes therethrough unduly close to one another; it also provides the openings
where necessary, for the passage of the hot gases between the tubes. Where the
gases are not to pass through openings formed in the manner described, rings are
provided which form closures to the openings in question.
In communication with the upper annular chamber there may be provided a
steam dome and separator comprising a vertical steam pipe that is in communica-
tion with the steam space of the annular chamber and has arranged centrally
within it a relatively small open-ended pipe, the lower end of which is below the
level of the water in the upper annular chamber. This small pipe is perforated
at intervals of its length and has attached to it a corresponding number of separat-
ing devices each comprising a lower funnel or cup-shaped part of less diameter than
the steam pipe and adapted to conduct any water flowing into it towards one of the
perforated parts of the central pipe and an upper truncated cone-shaped part the
upper edge of which is in contact with the wall of the steam pipe and the lower
edge of which is somewhat above and of less diameter than the upper edge of the
lower part; the upper part is supported on the lower by legs preferably so formed
as to form guides down which the water flows. With this arrangement the steam
and water is deflected by the lower part of each separating device against the wall
of the steam pipe and the back or outside of the upper part, the steam passing under
the lower edge of the latter, whilst the separated water flows down the back of the
upper part into the lower part, whence it passes through the perforations into the

page_text: central pipe back to the water space of the upper annular chamber. For use on a
vehicle the generator is preferably provided with a separator of this kind of
considerable height.
Referring to the accompanying illustrative drawings,
Fig. 1 shows in central vertical section a steam generator according to this
invention.
Fig. 2 shows a plan of the generator, partly in section.
Figs. 3 and 4 are a vertical section and a plan respectively of a steam dome and
separator according to this invention and Fig. 5 is a developed face view of the
upper part thereof.
The upper annular steam and water chamber is represented as being constructed
of two main parts namely an annular part 1 of U section with outward flanges 2
which may be of cast metal or may be of pressed steel and an annular tube plate 3
to which the part 1 is connected by bolts 4 passing through its flanges. 5 is the
opening through which fuel is fed and 6 the fire door, which is counter-weighted
so that it will remain open without being held.
The lower annular water chamber resembles the upper annular chamber but is
much shallower and comprises an annular part 7 of U or channel section with
Hanges 8 and an annular tube plate 9, these being secured together by bolts 10.
The upper and lower annular chambers are connected by water tubes 11 and 12,
the construction and arrangement of which will be understood from the description
already given aided by reference to the drawings.
In the example, the tubes 11 constitute the inner row and the tubes 12 the outer
row but there might be more rows. 13 is the fire grate and 14 the chamber or
casing below it; 15 is the movable ash pan. 16 is the outer casing of the generator;
17 the fan casing; 18 the fan, whose blades are or may be as represented straight
and radial so as to have an exhausting action whether driven backwards or.for-
wards. 19 is the funnel, which may be connected to the fan casing in full lines
in Fig. 1, or the fan may discharge the products of combustion downwardly into a
passage or flue as indicated by dotted lines. The course of the products of com-
bustion is indicated by arrows; they ascend to the upper part of the firebox, pass
outward radially through the spaces between the upper parts of the tubes 11, then
descend through the space between the two rows of tubes, from the bottom of
which they again pass outward radially through the spaces between the lower parts
of the tubes 12 into the space between them and the casing 16 whence they pass to
the funnel or flue. If a fan be employed as in the example, which is necessary
when the funnel cannot be made high enough to create sufficient draught, the
products of combustion are drawn through the fan casing and discharged either
into a funnel or downwardly to a flue. 20 is a ring arranged opposite to those
portions of the tubes of a row between which there are openings through which the
passage of hot gases is to be prevented. In the case of a boiler with more than two
rows of tubes other rings 20 would be provided where necessary. 21 is a baffle
plate for preventing the flame coming directly into contact with the tube plate 3.
22 is the steam pipe forming a steam dome and containing a central open-ended
pipe 23 (see Figs. 3 and 4) (which may be of larger diameter than the drawings
indicate); it is perforated at 23"; to it are attached separating devices each
comprising a lower part 24 and an upper part 25 that is formed with legs 25 and
has the portions of its lower edge that are between the legs suitably curved
(see Fig. 5) for the purpose of causing the separated water to flow towards and
down the said legs, thereby leaving a free passage for the separated steam and
obviating liability of the steam and water to become again mixed. The legs 25°
may, if desired, be formed with external grooves which serve as channels for the
water.
The fire bars may with advantage be riveted together in separate groups so that
when it is necessary to clean the fire, the central group can be removed, by pulling
it out with a firing tool, and the clinkered fire be pushed through the opening thus
formed in the grate and allowed to fall into the ash pan.

page_text: Fig. 6 is a view corresponding to Fig. 1 of a modified construction of generator
in which the capacity of the upper steam and water chamber is comparatively
small and a steam and water cylinder or drum 26 in connection therewith is
provided. It is in communication through a pipe 27 with the steam and water
chamber, and through a downtake tube 28 with the lower annular water chamber.
In this case a steam separator may be dispensed with, steam being led away from
the upper part of the cylinder or drum 26.
In order to ensure as far as possible that the passage of the products of
combustion shall take place evenly around the firebox and not by a short course
to the fan or chimney, a plate, such as 29, Fig. 6, may be arranged to extend
partly along the outer row of tubes.
Having now particularly, described and ascertained the nature of my said in-
vention and in what manner the same is to be performed we declare that what we
claim is:
1. A steam generator in which an upper annular combined steam and water
space with steam dome and annular tube plate, opening for feeding fuel, fire door
and baffle, a lower annular water chamber with tube plate, connecting walls of
wrter tubes, a fire grate, a chamber or casing below it, an ash pan, an outer casing
and hot gas arresting ring or rings, are constructed combined and relatively
arranged substantially as hereinbefore described and illustrated in the accompany-
ing drawings, whether a funnel or fan arranged in a suitable casing be employed
for producing the requisite draught as set forth.
2. The improved steam generator shown in and described with reference to
Fig. 6 of the accompanying drawings.
3. A steam generator of the kind referred to in claim 1 provided with combined
steam dome and separator substantially such as herein before described and
illustrated more particularly in Figs. 3, 4 and 5 of the drawings.
Dated this 2nd day of June 1807
Dated this 2nd day of June 1807
For the Applicant,
W. LLOYD WISE.
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.