Improvements in and relating to Steam-generators.
Year: 1891

page_text: Date of Application, 9th Jan., 1891
Complete Specification Left, 29th Sept., 1891-Accepted, 31st Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in and relating to Steam-generators.
I, GEORGE GATTON MELHUISH HARDINGHAM, of 191, Fleet Street, in the
City of London, Civil Engineer and Patent Agent, do hereby declare the nature
of this invention (a communication from Thomas Francis Morrin, of Jersey City,
in the County of Hudson, State of New Jersey, United States of America,
Engineer) to be as follows:
:-
This invention relates to that class of upright steam-generators wherein the
generating chamber is set in an upright casing and has laterally-projecting bent
generating tubes, the extremities of which are fixed by expansion or otherwise in
the upright generating chamber or cylinder at different levels and in different
vertical planes. These bent generating tubes are so arranged as to afford the
maximum amount of heating surface; the grate being annular and the flames and
heated gases ascending through and among them to the chimney.
The first part of this invention consists in the arrangement of the generating
tubes. In some cases, these tubes have prolongations within the generating
chamber extending from either their upper or lower ends to an upright cylinder
placed within the generating cylinder, preferably concentric therewith. The object
of this construction is to facilitate the circulation of the water through the tubes.
Above the water level, within the outer casing are similar bent tubes, which
extend laterally from the upper part of the generating chamber and form drying or
superheating tubes for the steam. That is, there are partitions across the upper
portion of the generating chamber and between the upper and lower extremities of
each tier of tubes, so that the steam flows out through the first tier of tubes above
the water-line, back above the first and below the second partition in the generating
cylinder, thence through the second tier of tubes in the same manner, and finally,
after passing through the several tiers of drying tubes, back into the extreme
upper part of the generating cylinder, which forms the steam dome. From this
dome, the dry steam is led by a pipe or pipes to the place where it is required. At
the base of the generating cylinder and below the line of rivets which secure the
bottom therein, the wall of the cylinder is cut away at intervals to facilitate
inspection.
The second part of this invention consists in the construction of the casing which
encloses the generating cylinder. This casing, which is usually cylindrical and
concentric with the upright generating cylinder, is built up of superposed drum-like
sections or rings of sheet metal; each drum or ring being made up of a number of
flanged sections or segments bolted together. Each section of the casing is lined
with fire tiles or "terra cotta lumber; " each tile or piece being secured to the
wall of the casing by a bolt or other securing device. This enables any part of the
lining to be removed independently of the remainder. The general construction
permits each section of the casing to be taken out individually for repair, or allows
the casing to be set up in a limited space, section by section. Doors are provided
in the sections of the casing to afford access to the tubes of the generator. The
refractory lining tiles are preferably made hollow at the back or outside, so as to
leave air-spaces between them and the metal of the casing.
The lower part of the casing contains an annular fire-box provided with an
annular grate or fire-bed; and the special construction of this annular grate,
whereby it is made rotative, constitutes the third part of the invention. In confined
places where access can only be afforded to the fire-box and ash-pit at one point,
the bed is rotatively mounted and provided with a rack and pinion, or other
suitable means, so that the stoker can bring any part of the fire-bed opposite the

page_text: charging door, in order that he may be able to feed and stir the fire at all points.
An ash-scraper is also carried by the rotating grate, whereby the ashes are brought
to the ash-pit door. The rotating grate and the ash-scraper need only be used,
however, under the conditions above referred to.
Dated this 0th dox of La 1901
G. G. M. HARDINGHAM.
COMPLETE SPECIFICATION.
Improvements in and relating to Steam-generators.
I, GEORGE GATTON MELHUISH HARDINGHAM, of 191, Fleet Street, in the
City of London, Civil Engineer and Chartered Patent Agent, do hereby declare
the nature of this invention (a communication from Thomas Francis Morrin, of
Jersey City, in the County of Hudson, State of New Jersey, United States of
America, Engineer,) 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 that class of steam generators wherein the generating
chamber is set in an upright casing, and has laterally-projecting bent generating
and drying or superheating tubes, and a fire-box and grate.
In the accompanying drawings, a steam-generator is illustrated which embodies
the present improvements.
Fig. 1 is a view, partly in section and partly in elevation, of such generator;
Fig. 2 being a horizontal section on the line 2, 2 in Fig. 1. The remaining views
are drawn to a larger scale.
Fig. 3 is a vertical section through the base of the furnace shewing the manner
of mounting, and the mechanism for operating, the annular rotating grate.
Figs. 4 and 5 are detail views representing different arrangements of the bent
generating tubes.
Figs. 6, 7 and 8 illustrate the construction of the sectional casing of the
generator.
Figs. 9 and 10 shew the construction of the bottom portion of the generator-
cylinder.
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A is the sectional casing, which is placed above the fire-box casing A¹. The
sectional casing is composed of a drum or drums, which or each of which consists
of flanged segments; the flanges enabling the segments or the segments and the
drums to be bolted together. A complete segment, with a flange formed integrally
on the margin of the metal plate a, is represented in Fig. 6. The inner face of a
part of the segment is shewn in Fig. 7; the flange being, however, made of angle
iron. Each segment a is lined with tiles of fire-clay, terra-cotta, or other similar
refractory material. Each tile is independently secured to the segment a by a
bolt d or other fastening. To prevent injury by heat, the head of the bolt lies in
a recess in the tile (Fig. 7); the recess being stopped with fire-clay or like
substance. To keep the metal plate as cool as possible, the back or outer face of
each tile is recessed or partly cut away, as shewn. These tiles are made to
conform to the shape of the casing, and may be of any convenient size. Fig. 8
illustrates the application of the tiles to a casing having a flat instead of a concave
surface. The casing has doors e (also lined with tiles) for providing access to the
interior for lighting the fuel, for inspection, and for the admission of a jet of steam
or air to clean the generating tubes.
The steam-guage f and the water-guage g are of the usual kind.
In the casing, and preferably concentric therewith, is set the generator-cylinder h;
around this cylinder (see Fig. 3), in the fire-box of the generator, being an annular
rotary grate i. The grate-bars are mounted on a ring-like carriage j, which rests
on rollers k at its inner and outer margins. On the under side of its outer margin,
the carriage has a circular rack 1, whereby the grate is rotated through the
instrumentality of a pinion m, the gearing n and a crank o. The latter and the

page_text: gearing n may be placed in any convenient position with respect to the charging
.door 22. In Fig. 3, for convenience of illustration, they are shewn as being placed
directly beneath the door, but they are usually at one side thereof, as in Fig. 1.
The rotating grate is well adapted for generators placed in confined situations,
where access can be had only to one side thereof. In order to facilitate the cleaning
out of the ashes from the ash-pit q, and the bringing of the ashes up to the ash-
door r, the carriage is provided with a scraper s, which extends into the ash-pit
and acts as a sweeper while the grate is being rotated. This scraper is preferably
made removable. Any other device than the rack and pinion shewn may be
employed for rotating the grate; as, for instance, a lever carrying a pawl adapted
to engage with a circular rack on the rim of the carriage j.
Figs. 9 and 10 clearly illustrate the construction of the base of the generating
cylinder h. The bottom is concavo-convex. The cylinder extends down below
the bottom; a clear space being left between the bottom and the base-plate t. The
wall of the cylinder below the line of rivets by which the bottom is attached is cut
away at intervals to form apertures u. These serve for the admission of air and
permit the head ' to be inspected. The cylinder is secured to the base-plate by
angle-pieces h².
v are the bent generating tubes, the shape of which is best seen in Fig. 2. The
lower extremity of each tube is expanded in the cylinder h; the upper extremity
being also expanded in the cylinder, but at a higher level, and in a different
vertical plane. The object is to introduce as many bent tubes as possible, and in
practice the arrangement represented in Figs. 1 and 2 produces the best results.
The tiers of generating tubes v extend from the fire-box up to or a little above
the water-line a. Above the water-line are arranged the drying or superheating
tubes w, which may have the same form as and be arranged like the generating
tubes. To compel the steam on its way to the steam-dome y (shewn in dotted lines
in Fig. 1) at the top of cylinder h to pass through each tier of tubes w in succession,
partitions are placed in the cylinder; one between the upper and the lower
extremities of the tubes in each tier.
As represented in Fig. 1, the tubes venter the cylinder equally at each end,
and there is no inner cylinder in the cylinder h. It is, however, sometimes desirable,
in order to increase the circulation of water in the tubes, to place within the
cylinder an open-ended cylinder a¹ (Fig. 4), and to put a thimble 62, reaching to
the said inner cylinder, on the lower extremity of each tube v. Or, the inner
cylinder may be connected with the upper instead of the lower extremity of each
tube v (Fig. 5); in which case the inner cylinder is closed at the bottom.
The steam is led away from the steam-dome by a pipe B or pipes. The feed-
water pipe c may be connected to one extremity of a heating coil ² arranged,
within the casing A, above the tiers of pipes w, as in Fig. 1; a pipe leading from
the other extremity of the coil c² down to the lower part of the generating
cylinder h.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I claim :-
:-
1. The improved steam-generator constructed and operating substantially as
described with reference to the accompanying drawings.
2. A steam-generator comprising a sectional casing A, a fire-box casing A',
a cylinder having a bottom and apertures u, a base-plate t, and generating
tubes v, substantially as herein described.
3. In a steam-generator, a sectional casing A comprising flanged plates a-lined
with recessed tiles c, each of which is independently secured by a protected bolt d
or other fastening, substantially as herein described.
4. In a steam-generator, the employment of generating tubes v arranged
substantially as described with reference to Figs. 1 and 2 of the accompanying
drawings.
5. In a steam-generator, a cylinder having a concavo-convex bottom /', below

page_text: which it is cut away at intervals to form apertures u, substantially as and for the
purposes herein set forth.
6. A steam-generator comprising a sectional casing A, a fire-box casing A¹, a
cylinder h, generating tubes r, drying or superheating tubes w, and partitions 2,
substantially as herein described.
7. A steam-generator comprising a sectional casing A lined with tiles c, a
cylinder, generating tubes r, drying or superheating tubes w, partitions 2,
a rotating grate i, and a carriage and scrapers, substantially as herein
described.
8. A steam-generator comprising a casing A lined with tiles c, a fire-box
casing A', a cylinder having a bottom h', generating tubes v, drying or super-
heating tubes w. partitions, a rotating grate i mounted on a carriage furnished
with a scraper s, and a feed-water pipe connected to one extremity of a heating
coil c², the other extremity of which coil leads to the lower part of the generating
cylinder h, substantially as herein described.
9. A steam-generator comprising a casing A lined with tiles c, a fire-box
casing A', a cylinder having a bottom ', generating tubes v connected by
thimbles with an open-ended cylinder a' within the cylinder h, drying or super-
heating tubes w, partitions z, a rotating grate i mounted on a carriage j furnished
with a scraper s, and a feed-water heating coil, substantially as herein
described.
Dated this 26th day of September 1891.
G. G. M. HARDINGHAM.