Improvements in Steam Generators.
Year: 1892

page_text: COMPLETE SPECIFICATION.
Improvements in Steam Generators.
I, HENRY CHAPMAN BAGOT, of Glyn, near Conway, in the County of
Carnarvon, Mechanician, 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 steam generators; its objects being to enable steam to
be quickly and economically raised, to provide for a high pressure being safely
maintained, to effect the consumption of smoke, to gain strength and lightness, to
secure portability, and to increase the capacity of the fire-box with a view
to securing the proper mingling of the gases.
In the accompanying diagrams, which serve to illustrate the way in which I
prefer to carry out this invention, Fig. 1 is a front elevation of the improved steam
generator; Fig. 2 being a corresponding plan. Fig. 3 is a vertical section through
one of the spherical elements of the generator, shewing the water space, the
elliptical hollow fire-bars, and the water-tubes; Fig. 4 being a corresponding front
elevation. Figs. 5 and 6 are views similar to Figs. 3 and 4, but representing a
modification. Fig. 7 is a horizontal section shewing the fire-bars; the water-tubes
being removed. Fig. 8 is a front elevation of the support for the elliptical fire-
bars; one of the fire-bars being also included in this figure.
Each
A, B and C are three spherical shells. Each is formed in halves, which are
rivetted together. They may be made of steel boiler plates, fluid compressed steel
or other metal. Another spherical shell D, furnished with the usual feed-pipes,
gauges, valves, etc. (which are omitted in the diagrams), is placed on the top
of the three shells A, B and C. The shell A is connected to the shell Ď
by two pipes a and a'; the shells B and C being similarly connected by the
pipes b, b, c and c. This arrangement ensures free circulation. There is ample
steam space in the shell D. The water is at such a level in the shell D as to
provide for an abundance of water over the crowns of the fire-boxes. Each of the
shells A, B and C is fixed on a suitable support or supports. The shell D may
also be furnished with a support in addition to the pipes a, a, b, b, c and c².
of the shells A, B and C is provided with a spherical fire-box E (Fig. 3); a
water-space F being left between the shell and its fire-box. The fire-box per-
taining to the shell A is connected to that pertaining to the shell B by a flue A¹,
that in B to that in C by a flue B', and that in C by a flue C¹ to the stack_or
chimney. Each of the shells A, B and C has in its fire-box a series of fire-bars E¹.
At starting, the fuel in the shell C is fired first, because it is nearest the chimney,
then the fuel in B, and lastly the fuel in A. Subsequently, A is fired hardest, and
B is fired harder than C, in order to ensure the full consumption of the smoke as it
passes through C on its way to the chimney. The fire-bars E' are elliptical in
cross section, and are carried by a support ex. Each fire-bar is hollow, and serves
to convey air to the back of the fire-box. The rear end of each fire-bar may be
turned up and directed forwards. Air can also pass freely between the bars when
each bar is in the position represented in Fig. 8 its transverse diamater being in a
vertical plane. The bars can, however, be turned over sidewise, their conjugate
diameters then lying in vertical planes, as indicated in dotted lines in Fig. 8. In
this position, the fire-bars nearly touch one another, so that the area of the
interstices for the direct admission of air to the fuel on the fire-bars is considerably
diminished. The fire-bars may be turned into either position by pins, such as e,
projecting from a rack E'; one of these pins entering each of the hollow bars.
The rack E' is caused to move to and fro by means of pinions e. By bringing

page_text: the rack E2 near to or in contact with the open ends of the hollow fire-bars, the
admission of air through the bars to the back of the fire-box can be regulated or
cut off altogether. The movement of the fire-bars by means of the rack also
serves to clean then. E* are solid cast fire-bars. The bent or doubled water-tubes G
pass from the shell through notches in the sides and top of the furnace-door into
the fire-box above the fire-bars E', where they rest on the support g. Each end of
each bent water-tube is furnished with a stop-cock fitted to the shell. The water
in these tubes becomes quickly heated, thus increasing the steam-producing qualities
of the generator. In the modified design shewn in Figs. 5 and 6, the water-tubes G
pass directly from the ring g', so that the notches in the furnace-door are not
required; the door L closing over the bent ends of the tubes. In this case, the
stop-cocks are fitted to the ring instead of to the shell. The water-tubes G may
serve to support other coiled water-tubes. H is the ash-pit. K is the blow-off
cock. A spherical mud-receiver is placed below the level of the bottoms of the
shells A, B and C, into which each can blow off. The double-flanged ring gl near
the furnace and the similar ring g² near the flue connect the fire-box with the
shell.
The shell and fire-box may be corrugated, or the latter only may be so
formed.
the furnace can be supplied with heated air by introducing an inlet pipe M
(Fig. 6) between the shell and the fire-box. Cold air entering the pipe becomes
heated on its way to the outlet end of the pipe by the hot water in the water-space;
the outlet being preferably situated just inside the door L. This pipe may, how-
ever, pass through the water-space into the fire-box; the air being principally
heated, under such circumstances, by the hot gases in the fire-box instead of by the
water in the water-space. A fan or other device may be used for forcing the air
through the pipe M; thus causing the air to be thoroughly diffused in the furnace
and effecting the more perfect combustion of the fuel. A hopper containing fine
coal dust may be provided; the coal dust being allowed to fall under the influence
of gravity and at such a rate as may be required into the current of air passing
through the pipe M, thus considerably adding to the heat-giving qualities of the
furnace.
As the improved generator is built up of elements made in sections, the largest of
which can be easily carried, it follows that this generator is particularly suitable
for transport over steep and difficult roads. The various sections can, moreover,
instead of being rivetted together, be secured by flanges and bolts; thus facilitating
the assemblage of the parts on the destination being reached.
Each flue may have a fire-brick or similar lining.
Each of the shells or elements A, B and C has a small hole near the top through
which a brush with a flexible handle can be passed while the water-space, the
surfaces of which should be as smooth as possible, is being washed out. The
shell D is provided with a man-hole.
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, arranged and operating sub-
stantially as described with reference to the accompanying diagrams.
2. A steam generator comprising three spherical shells A, B and C, each
containing a spherical fire-box E, and a steam shell D placed above the other shells,
substantially as herein described.
3. A steam generator comprising a series of independently-fired elements con-
nected to one another and to the stack or chimney, so that the smoke from the
farthest element passes through the fire-boxes of the other elements on its way to
the chimney, and the smoke from the elements less remote through the elements or
element nearer to the chimney, substantially as herein described.
4. In a steam generator, an element comprising a shell A, a fire-box E, fire-
bars E', a water-space F, and water-tubes G, substantially as herein described.

page_text: 5. In a steam generator, the employment of hollow fire-bars E' which serve to
convey air to the back of the fire-box, substantially as herein described.
6. In a steam generator, the employment of elliptical hollow fire-bars E' which
can be turned sidewise for the purpose of diminishing the supply of air to the
furnace, substantially as herein described.
7. In a steam generator in which elliptical hollow fire-bars are employed, the
means for regulating the supply of air therethrough and for turning the same,
substantially as herein described.
8. In a steam generator, heating the air admitted to the furnace by placing the
air-inlet pipe in or passing it through the water-space between the shell and the
fire-box, substantially as herein described.
9. In a steam generator, forcing air by means of a fan or equivalent device
through an air-inlet pipe placed in or passing through the water-space between the
shell and the fire-box, substantially as herein described.
10. In a steam generator in which air is forced through an air-inlet pipe placed
in or passing through the water-space, allowing coal dust to fall under the influence
of gravity into the current of air forced through the pipe, substantially as herein
described.
Dated the 27th day of May 1900
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Chartered Patent Agent.