IMPROVEMENTS IN GENERATING STEAM OR VAPOR, AND IN APPARATUS THEREFOR
Year: 1873

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery
Lane, in the County of Middlesex, Patent Agent, for the Invention
of "IMPROVEMENTS IN GENERATING STEAM OR VAPOR, AND IN APPARATUS
THEREFOR."-A communication from abroad by Benjamin Douglass,
of Montrose, in the County of Essex, and State of New Jersey,
United States of America.
Scaled the 13th February 1874, and dated the 26th December 1873.
COMPLETE SPECIFICATION filed by the said Alexander Melville Clark
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 26th December 1873, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN GENERATING STEAM OR VAPOR, AND IN APPARATUS THEREFOR," and have
petitioned Her Majesty to grant unto me, my executors, administrators,

page_text: and assigns, Her Royal Letters Patent for the same, and have made
solemn Declaration that it has been communicated to me from abroad
by Benjamin Douglass, of Montrose, in the County of Essex, and State
of New Jersey, United States of America.
NOW KNOW YE, that I, the said Alexander Melville Clark, do hereby
declare that the following Complete Specification, under my hand and seal,
fully describes and ascertains the nature of the said Invention, and in
what manner the same is to be performed, in and by the following
statement, reference being had to the Sheet of Drawings hercunto
annexed, and to the letters and figures marked thereon (that is to
say) :-
This Invention relates to the instantaneous development of steam and
vapour from fluid substances by application of the substances to highly
heated surfaces in expanders. The essential feature of the Invention is
a series of hollow spherical balls or expanders with a feed pipe and jet
bulb to cach, so arranged that cach receives its due measure of feed in
such small quantity that the force of the instantaneous expansion is
controllable by the balls, and the vapour produced is sent therefrom along
with that from the other balls to the pipe, which conducts it to the
engine in such manner that there is no accumulation anywhere larger
than the conducting passage, so that the great pressure attainable by the
direct contact of the fluid with the red hot metal can be controlled as
it could not be in large chambers affording any considerable accumu-
lation.
Another important feature of the Invention is an arrangement of the
expansion balls in the furnace so as to bo directly surrounded by the fire
so as to bring the fluid intot he most direct contact with the highest heat
of the fire, whereby a great economy of heat is effected over the ordinary
way of arranging the heating surface above and beyond the firo,
because the higher the heat is the faster it passes through the con-
ducting substance; thus it not only passes quicker to the fluid, but
because of passing quicker less surface is required for conducting a given
quantity.

page_text: The economy in area of heating surface which is thus secured, together
with the economy due to the instantaneous expansion of the fluid by
direct contact with a hot surface, enables a given quantity of power to
be produced with very much smaller generating surface than that
required by the ordinary process. But there is another economy resulting
from this arrangement in the burning of the fuel, which in consequence
of the direct contact of the heat can be very slow and yet have the heat
much greater at the point of application to the conducting surface than
in the ordinary way, and thus all the advantages of economy by slow
combustion is obtained, whereas the common process requires rapid and
wasteful combustion.
Another essential advantage of the system is large economy of space
on account of having no large body of water in the generator as in the
common system.
Another advantage is in the facility it affords of regulating the amount
of power produced and gauging it to any predetermined point by regu-
lating the quantity of feed admitted or stopping the production altogether
by shutting off the feed, so that in case the engine stops there is no
further production till wanted again, when the production may be
instantly re-established by letting on the feed. There is no dangerous
accumulation of power while stopping, and there is no danger of material
damage from explosion at any time, because if any part gives way the
quantity of steam or vapour escaping is so small that its force is not very
dentation
O cusmon be used in connection with the 10eu.
Figure 2 is a transverse sectional elevation of the generator.
Figure 3 is a horizontal section of the generator.
Figure 4 is an enlarged detail section of one of the hollow expanders
and the feed tubes and a connection of the expanders.
And Figure 5 is a section of a half-ball expander, which is employed
on the sides of the furnace. It also shows a section of a portion of the
shell of the furnace, also the connection of said ball with the shell, also
the connection of the series of half balls, and also the feed connection.
Similar letters of reference indicate corresponding parts.

page_text: The form of the shell of the generator as represented in the Drawings
is not particularly essential, although it possesses some advantages that
may make it preferable in some cases; yet I contemplate other forms,
for instance, it is well adapted to the cylindrical form, either vertical or
horizontal.
A represents the shell, which is double walled to form a water space B
for surrounding the fire chamber C to intercept the radiating heat as
much as possible. D is a pipe or dome upon the top, into which the
products of combustion pass to enter the escape flue E; Fis the fire-grate;
G is the ash chamber below; H, doors to the ash chamber; A³ a damper 1
in the smoke flue; I represents the hollow spherical ball expanders for
the interior portion of the fire chamber; and J, the half-ball expanders
for the sides; L, a large powerful air cushion apparatus through which
the feed water passes; M, a coil in the dome into which the main fced
pipe discharges; N, is a connection of the coil M, with the jacket 1
chamber B to conduct the feed water into said chamber; O, feed
pipes conducting the feed water from the jacket chamber B into the
expanders I; P, a pipe receiving the water from the jacket, and deliver
ing it to the branches O through a regulating cock; Q represents the
feed pipes for conducting the water from the jacket chamber B to the
half-ball expanders J; R, the regulating cock to control the feed. These
feed pipes Q and the regulating cock are duplicated on the other side of
the generator for the half-ball expanders on the other side, also on the
front and back, but in this example they are not represented on the
front. In practice it would be preferable to have the feed pipes Q and O;
proceed from one source, so as to use only one cock for regulating all
the jets, and the feed pipes may also be arranged within the jacket to
avoid exposure to the atmosphere, so that considerable heat will be
saved.
It will be observed that the feed water passes first into the coil M, &
where it is first raised by the escaping heat to about two hundred and
sixty degrees, then it passes into the jacket chamber, where it is further
heated to about five or six hundred degrees, and then it passes into the

page_text: The expanders I are connected together by the thimbles a, screwed into
the hollow screw threaded bosses b, and the rows of expanders are con-
nected together as at,d, e, and f, or in any equivalent way, so that the
vapour will be conducted to one passage common to all, say 9, and con-
necting with the pipe to the engine. The half expanders are similarly
connected together by thimbles and bosses as a, b, and the several rows
are also connected together and to the passage g. h, i, j, k, and I,
represent the nest of feed pipes for one row of expanders I, and m the
perforated jet ball in each expander in which the feed pipe terminates.
These are connected at the front end of the row of expanders which
they feed with a perforated cone n inside of a hood p, to which the
feed pipe is connected at q, so that each receives an equal proportion
of the feed water through holes 7 and 8, which are suitably proportioned
for the purpose.
At the perforated jet bulbs m the feed is broken up into fine jets as it
issues into the red hot expanders, so that the development of vapour is
instantaneous. The half expanders J receive the feed through a pipe Q,
extending through a hollow bolt 6', passing through a thimble C', which
extends through the side of the boiler and projects a little at & into the
hollow boss d on the side of the expander, which keeps it a certain
distance from the side wall of the furnace, so that the fire will act upon
that side of the expander and upon the furnace side. The bolt 6¹ screws
the boss d³ of the expander firmly against the furnace wall, and binds
the head of the thimble against the outside wall.
Other modes of attaching the half-balls may be employed, if preferred,
but whatever the arrangement may be it is desirable that the expanders
be held out sufficiently from the furnace wall for the action of the heat
between them as stated.
The coal is to be fed into the fire from the top through a couple of
feed holes D', one on each side of the dome, upon and around the
expanders, to the top if desired, or to any extent that may be required
by the work in hand. The rate of combustion will be regulated by the
draft let in at the bottom in any way.
When the water jets are let into the red hot expanders the expansion
is so sudden that the pressure instantaneously established reacts too
powerfully upon the feed pump to be resisted by the ordinary pump
cushion, which is only used to relieve the shocks due to the changes of

page_text: 4th. The combination of the perforated jet balls with the feed tubes
and expanders, when arranged in close proximity to the surface of
the expanders, to discharge the water directly thereon, substantially as
specified.
5th. The series of pipes arranged to form the cone n, having perfora-
tions r, s, in combination with a chamber p of a supply pipe, as shown
and described.
6th. The combination of half-ball expanders J with the sides of the
of the furnace, substantially as specified.
7th. The connection of the half-ball expanders by the tube 0', hollow
bolt 6', and boss d³, substantially as specified.
8th. The arrangement of the branched feed pipos O and Q and regu-
lating cocks with the expanders, so as to feed each row of expanders,
and regulate the amount of the feed to the pressure required, substan-'
tially as specified.
9th. The management of the main feed pipe K, coil M, connection N,
jacket chamber B, feed pipes O and Q, and the expanders to apply the
feed in the order described.
In witness whereof, I, the said Alexander Melville Olark, havo
hereunto set my hand and seal, this Twenty-sixth day of
December, in the year of our Lord One thousand eight hundred
and seventy-three.
A. M OLARK (7.0)