IMPROVEMENTS IN STEAM GENERATORS
Year: 1849

page_text: BROOMAN'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ARCHIBALD BROOMAN, of the Patent Office, 166, Fleet Street, in the City of
London, Patent Agent, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fourth day of July
One thousand eight hundred and forty-nine, in the thirteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Richard Archibald Brooman, my exors, adñiors, and assigns, Her
especial licence, full power, sole privilege and authority, that I, the said Richard
Archibald Brooman, my exors, admors, and assigns, and such others as I, the
said Richard Archibald Brooman, my exors, adiňors, or assigns, should at any
time agree with, and no others, from time to time and at all times during
the term of years therein expressed, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, the Invention of "IMPROVEMENTS IN STEAM GENERATORS," communicated
to me from abroad; in which said Letters Patent is contained a proviso that
I, the said Richard Archibald Brooman, should cause a particular descrip-
tion of the nature of the said Invention, and in what manner the same is
to be performed, by an instrument in writing under my hand and seal, to be
inrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more fully
and at large appear.

page_text: Richard Archibald Brooman, do hereby declare that the nature of-the-said-
Invention, and in what manner the same is to-be performed, are fully-described
and ascertained in and by the present Specification thereof, reference being
had to the Drawings hereunto annexed, that is to say:-
The Invention is based upon the recent discoveries, by Bontigny, of Evreux,
of the peculiar properties which bodies in a spheroidal state acquire on being
projected in small quantities upon a surface heated to from 400° or 500° centi-
grade, and consists in the construction and arrangement of apparatuses for
applying them practically to the obtaining of motive power, and to the various
manufactures for which steam (of a much lower temperature) has hitherto
been employed. Before proceeding to the description of these apparatuses, it
will be proper to give some preliminary explanation of what is meant by "the
spheroidal state of bodies," and what the "peculiar properties" are, before referred
to. A body, water for instance, on being projected in small quantities and at
certain intervals of time, on the bottom of a suitable recipient which is heated
to from 400° to 500° centigrade, while its sides are maintained at a tempera-
ture below 142° centigrade, assumes a rounded or spheroidal form, which
remains at a permanent distance from the spheroidalizing body—that is, the
body of the recipient and reflects radiated heat. Its chemical action is
suspended; and its temperature, invariable or confined within very narrow
limits, always beneath the boiling point, while the steam which it throws off at
a slower rate than it would do if heated in the ordinary manner, is of the same
temperature as that of the spheroidalizing surface. The water in contact with
the sides vaporises immediately, and, if the recipient is closed, will pass into
equilibrium temperature and pressure with the steam which is continuously
given off by the spheroids.
It follows from what has just been stated, that this system of steam genera-
tion is attended with these advantages:―
First, that a very considerable quantity of caloric and dynamical force may
be contained in a very small volume of steam, in consequence of the high
temperature and pressure which are given to it in generators of from fifty to
one hundred times less size than ordinary steam boilers, to produce a like
result.
Second, that the steam formed by the water coming in contact with the sides
of a vessel at a temperature below 142° centigrade will be raised to a much
higher temperature and pressure by the radiation of heat from surfaces heated
to above 142° centigrade, and by mingling with the steam thrown off from the
spheroids.
:

page_text: Third, that the quantity of water in the generator may be considerably
reduced, without diminishing the motive power.
Fourth, that the size of the furnace, and quantity of fuel consumed, may also
be reduced, inasmuch as the heat arising therefrom may be applied first to the
bottom of the generator, then to the sides, and last to raising the temperature
of the feed water to above 100° centigrade.
Fifth, that the chances of danger from explosions are considerably lessened,
in consequence of the generator containing only a few quarts of water-a
portion in the liquid state, and the rest in the spheroidal state-so that should
any part of its spheroidalizing surface be suddenly cooled down to below 142°
centigrade, a certain known quantity of steam only can be disengaged, the
effects of which may easily be provided against.
The purposes to which steam of this high temperature, generated in appara-
tuses about to be described, may be most advantageously applied, are:-The
heating of stoves and apartments, baths, dyers and scourers vats, paper-making,
silk-spinning, cooking, manufacture of soap, distillation of wines, spirits, fatty
bodies and fatty acids, boiling of syrups, sugar refining, extraction of soluble
and coloring matters from vegetables, desiccation and baking of clay and other
substances, carbonization and revification of organic substances; fusion of
certain metals and other fusible products, roasting ores, &c. &c. An apparatus
suitable for generating steam in the manner before described is represented in
the Drawings hereunto annexed.
Figure 1 is a longitudinal section on the line A, B, and Figure 2 a cross
section on the line C, D, of Figure 3, which represents a plan of the apparatus
one tenth of its actual size. A is a cylinder of iron, or other suitable metal,
which forms the body of the generator, and is constructed of a thickness
capable of resisting the maximum degree of pressure to which it is to be
subjected. A is a cover bolted to the flange of the cylinder, and provided with
suitable orifices to receive the feed-pipe J" (placed in the centre), the exit or
surplus water escape pipe N, the safety valve R, S the steam pressure guage
and steam pipe M. a, a', a" a, are a number of circular concentric grooves
or channels, of from three eighths to half an inch in depth, and twice that in
breadth, or hemispherical. hollows communicating with each other, which are
constructed in the bottom of the generator for the purpose of separating the
feed water. Roughnesses or projecting angles on the surface of the generator
being unfavorable to the production of the spheroidal state; everything of the
sort should be removed by polishing and planing down. And in order to avoid
the existence of such angles, and to economize space as much as possible, a

page_text: portion of the circumference of each hemispherical hollow in the second row
is made to take into the space opposite to it, between the two chambers of the
first row, and so on throughout the series. Or, instead of the preceding,
any other convenient form and arrangement of chambers may be employed,
provided they divide the water into small portions, and surround each portion
with as much of the heated bottom of the generator as may be practicable. B,
brickwork or masonry in which the generator is set; and b, b, small flues therein
for conducting the heat and products of combustion from the furnace F around
the generator, previously to escaping by the chimney D, which is made of sheet
iron. C is a casing of sheet iron which envelopes the brickwork or masonry.
E, E, standards to support the furnace. G, G', are two feed reservoirs; con-
structed in sheet or cast iron, and to be used in cases when the water cannot
be supplied to the generator by a pump. H, H', are the supply pipes. I, I', the
discharge cocks of the reservoirs. J, J', two service pipes leading from the
reservoirs, and uniting in the feed pipe J". L, L', two pipes provided with
stop-cocks I, l', which are united at the point L", and open into the top of the
reservoirs for the purpose of maintaining equality of pressure between the supply
cisterns G, G', and the generator. This double system of supply has for its
object to prevent any stoppage in the supply to the generator, for during
the time one reservoir is emptying the other is filling. The four pipes L, L, J, J
are provided with stop-cocks, as indicated in the Drawings, for cutting off or
opening a communication between one or other of the reservoirs G, G', and the
generator, as occasion may require. N is a vertical pipe, being the prolonga-
tion of L", which terminates just above the top of the grooves or chan-
nels. 0, 0, 0, 0, are circular false bottoms, which are perforated and suspended
one beneath the other in the interior of the generator; they are moreover
provided with roughened edges all round, which serve to retain a portion of the
feed water which is vapourised by boiling, while the roughness of the sides
prevents the spheroidalisation of the water so retained. P, P, are two tubes
which communicate with the lower and upper parts of the generator A, as shown
in the Drawing Figure 1, and at their other ends with the vertical glass tube Q
for the purpose of enabling the height of water in the generator to be ascertained.
V is the weight on the end of the lever of the safety valve, and T the door of the
furnace; g, g', are vertical glass tubes, communicating at top and bottom with
the feed cisterns, for the purpose of indicating the height of water therein.
The mode of operation of the apparatus is as follows:-Supposing the
fire to be lighted while the reservoir is empty, and thereby. heated to
between 400° and 500° cent., the tap of one of the service pipes. J leading
.

page_text: from the reservoir G to the feed pipe J" is then opened, and the water
allowed to flow into and through the false bottoms successively, a portion
whereof is thereby vapourised, and the rest falls into the grooves or chan-
nels a, a', a", and passes into the spheroidal state. The pressure in the
generator is communicated to the feed cistern G by the exit pipe N and tube L,
the stop cock whereof being opened, while the stop cock of the tube L' is.
closed, so that the inflow of water is uninterrupted whatever may be the amount
of pressure in the generator, and the feed is rendered self-acting as it were. If
from any cause the level of the water projected on the bottom of the generator A
rises above the top of the edges of the grooves or channels, it will be immedi-
ately driven by the pressure of steam into the exit pipe N, and thence into the
feed cistern G; otherwise the water will remain in the pipe, whence it will fall
little by little, until equality of pressure is established between the feed cistern
and the generator, and the level of water in this latter is somewhat below the
top of the grooves or channels, It will be seen from the preceding observations
that the pipe N has to perform two functions; first, to maintain an equality of
pressure in the generator and feed cistern, in order that the inflow of water may
be uninterrupted; and second, to regulate the level of the spheroidalised water.
When the feed cistern G is emptied, the cocks which establish communication
between the top and bottom thereof and the generator A are shut off, and the
cocks of the pipes L', J', are turned on, and a similar communication opened
between the top and bottom of the feed cistern G' and the generator A. This
peculiar construction and arrangement admits of the supply of feed water being
diminished or stopped altogether without incurring any danger, a circumstance
which favorably distinguishes this from ordinary steam generators; the only
result being proportional decrease in the steam given off, which may however
be re-established by opening one of the feed taps. In the case where the
supply of water is too great, the exit pipe N will maintain it at a level beneath
the top of the grooves or channels, and consequently prevent the dangerous
results which would ensue if it overflowed them. In order to diminish the
chance of danger from explosions, the cover A' is constructed to resist a some-
what lower degree of pressure than the cylinder A, so that it may be the first
to give way, in which case it will be necessary only to replace the injured cover,
whereas any rupture of the cylinder would be attended with disastrous conse-
quences. And as further precaution, the generator may be placed in the lower
part of the chimney.
Figures 4 and 5 are a sectional elevation and plan of a modification of this
steam generator, in which the false bottoms are replaced by the spiral wire

page_text: gauze tube 0, 0; S is its point of junction with the pipe leading from the feed
pump or other source of supply. Part of the water in flowing through the
spiral tube is vaporised, and in the form of steam allowed to escape through
the reticulated surface of the tube, while the remainder falls into the grooves
or channels constructed in the bottom A' of the generator A, as explained in
describing Figure 1.
Figures 6 and 7 represent a sectional elevation and plan of another modifi-
cation, consisting of a double cylinder arrangement in which the heat and
products of combustion are caused to pass inside and outside, whereby the
extent of heating surface will be considerably increased. A is the exterior
cylinder; A", the interior one; A', the bottom, in which groves or channels
a, a', a, a, are constructed as before described; D, the chimney; O is a false
bottom, similar to those shewn in Figure 1, which receives the feed water in
the first instance, and allows it to fall into the tube O', similar to the spiral
tube described in speaking of Figures 4 and 5, whence it passes to the
gutter O", which conducts such portion as may not have been vaporised
in its passage to the grooves or channels, where it passes into the spheroidal
state.
Figures 8 and 9 are a sectional elevation and plan of another modification of
this apparatus. A, A', A", are a number of cylinders placed at right angles
to the receiving cylinder B, into which the feed water is supplied from several
points, and whence it runs down the slightly inclined bottoms of the cylinders
A, A', A". During its transit a portion of the water passes off in the form of
steam, and the rest passes into the spherodial state when it arrives at the
hemispherical shaped ends of the cylinders which are exposed to the greatest
amount of heat. Rectangular perforated metal trays may be placed in the
cylinders, for the purpose of increasing the heating surface. When it is desired
to maintain the generator at a constant temperature, a bath of metal, or of
some of the fusible alloys, or of metallic filings or other substances in powder,
may be employed as a heating medium between the generator and the
furnace.
In the Figures (4, 5, 6, 7, 8, and 9,) illustrative of the preceding modifica-
tions of the steam generator, several parts are omitted, such as the pumps,
valves, indicators, &c., because they differ in no material respect from the
corresponding parts represented in Figures 1, 2, and 3, and before described.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I do not confine myself to
any of the precise dimensions and relative proportions exhibited in the Drawings,

page_text: nor to making the grooves or channels in the bottom of the steam generator of
any peculiar form; but that the improvements which I claim as constituting
the said Invention are as follows:-
T
First, I claim the employment, for manufacturing and other useful purposes,
of steam of higher temperature and pressure than has hitherto been ordinarily
used, the same being generated from the combined action of the ebullition and
the spheroidalisation of water, as before exemplified and described.
Second, I claim the employment of perforated trays, spiral wire gauze tubes
and gutters, either alone or combined in connection with a steam generator, the
bottom whereof is hollowed out as before described, for the purpose of gene-
rating steam by the combined action of ebullition and spheroidalisation.
Third, I claim the employment of two concentric cylinders, heated in the
inside and outside, and arranged as represented in Figures 6 and 7, and before
described.
Fourth, I claim the employment of a number of cylinders, terminating at
the point where the greatest amount of heat is applied in hemispherical ends,
and opening at the other end into a transversal cylinder (to which the feed
water is supplied) either alone or in combination with perforated metal trays,
as represented in Figures 8 and 9, and before described.
Fifth, I claim the general arrangement of parts in connection with the two
feed cisterns for supplying the generator with water, as before described.
Sixth, I claim the employment of a pipe placed inside the steam generator,
terminating at bottom just aboove the top surface of the grooves or channels, and
communicating at top with the upper part of the feed cisterns, for the purpose
of maintaining equality of pressure in the feed cisterns and generator, so as to
ensure a continuous and regular supply of water to the latter; and also of
maintaining the level of the spheroidalised water at a point beneath the top
surface of the grooves or channels, as before described.
Seventh, I claim placing the said improved steam generator within the
chimney of the furnace, as before described.
Eighth, I claim the application of baths of metal, or other suitable substance,
to the heating of the improved steam generator, as before described.
In witness whereof, I, the said Richard Archibald Brooman, have here-
unto set my hand and seal, this First day of January, One thousand
eight hundred and fifty.
R. A. (L.8.)
(L.8.) BROOMAN.

page_text: AND BE IT REMEMBERED, that on the First day of January, in the
year of our Lord 1850, the aforesaid Richard Archibald Brooman came before,
our said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form above.
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Enrolled the Fourth day of January, in the year of our Lord One thousand
eight hundred and fifty.