Im- PROVEMENTS IN THE CONSTRUCTION OF STEAM GENERATORS AND CONDENSERS
Year: 1869

page_text: LETTERS PATENT Joseph Augustus Miller, of Boston, Massa-
chusetts, United States of America, for the Invention of "Im-
PROVEMENTS IN THE CONSTRUCTION OF STEAM GENERATORS AND
CONDENSERS."
SURFACE
Sealed the 7th January 1870, and dated the 29th October 1869.
PROVISIONAL SPECIFICATION left by the said Joseph
said Joseph Augustus
Miller at the Office of the Commissioners of Patents, with his
Petition, on the 29th October 1869.
1, JOSEPH AUGUSTUS MILLER, of Boston, Massachusetts, United States
of America, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF STEAM GENERATORS AND SURFACE
CONDENSERS," to be as follows:-
My Invention relates, firstly, to the novel construction of steam
generators in which the water is contained within tubes exposed to the
fire.

page_text: condensing surface consists of a number of tubes through which water
is passed, while the steam is brought in contact with the outer surface
of the tubes.
I construct a tubular steam generator with tubes arranged in such a
manner that only one end of each tube is permanently secured, the
other end being left free, so that the tubes may expand and contract by
the action of the heat, and I ensure the free circulation of the water
through the said tubes by means of other tubes placed within the first
or outer tubes, such inner tubes being open at both ends. At the front
end of the boiler is a chamber, which is divided vertically into two parts
by a plate extending from a point near the lowest water level to a point
somewhat below the lowest tube. Into one of the outer plates of this
chamber I secure one end of the outer or large tubes, and close tightly
the other end of the said tubes with a cap or cover, made in such a
manner as to also form a means for supporting this end of the tubes,
while leaving them free to expand or contract. The inner tubes are
secured at one end in the partition plate of the front chamber, and are
supported at their free end within the outer tubes by projecting pins
or wings, which hold them central with the outer tube, but do not
obstruct the circulation of the water therein. The tubes are then placed
in an inclined position over the fire in such a manner that the chamber is
the highest part, and so that the heated gases are compelled to pass
around and among the tubes. The ends of the outer tubes which are
secured in the outer plate of the main chamber open into the steam
space of the chamber, and the small tubes open into the return water
space of the said chamber.
As soon as heat is absorbed by the water
circulation commences, and the steam is allowed to pass freely into the
steam space, while the water continually enters through the inner tubes.
It will be obvious that as the diameter of the parts which sustain the
pressure is small great structural strength is obtained, and that as a
large heating surface is exposed to the fire there will be a rapid
generation of steam. The construction is simple and inexpensive, all
the material used forms efficient heating surface, the whole structure
consisting of a multiplication of similar parts. The caps on the free
end of the tubes are readily removable, so that the tubes may be cleaned
without difficulty, and worn out or defective tubes may be easily

page_text: removed and replaced by new ones. I construct surface condensers on
the same principle, that is to say, I secure tubes into plates only at one
end, and close the other end of the said tubes, leaving this closed end
free, so that the tubes may expand and contract under variations of
heat, and to ensure the free circulation of the water within the tubes
smaller tubes placed inside the outer tubes have their end secured in
another plate, such inner tubes extending nearly to the free end of the
first tubes; the water enters the inner tubes and returns through the
outer tubes in a thin film, which after absorbing the heat from the
steam is discharged by a suitable pipe. As only one end of the tubes is
fixed and the other free no packing is required, and there will be no
breaking of the joints by the expansion or contraction of the tubes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Augustus Miller in the Great Seal Patent
Office on the 28th April 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
AUGUSTUS MILLER, of Boston, Massachusetts, United States of America,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of October, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-third year of Her reign, did for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Joseph Augustus Miller, Her
special licence that I, the said Joseph Augustus Miller, my executors,
administrators, and assigns, or such others as I, the said Joseph Augustus
Miller, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF STEAM GENERATORS AND SURFACE CON-
DENSERS." upon the condition (amongst others) that I, the said Joseph
Augustus Miller, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-

page_text: ticularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Joseph Augustus Miller, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawings forming a part of this Specification:-
My Invention relates, firstly, to the novel construction of steam
generators of that class in which the water is contained within tubes
exposed to the fire.
And, secondly. To the like novel construction of surface condensers
whose condensing surface consists of a number of tubes through which
water is passed, while the steam or vapor to be condensed is brought in
contact with the outer surface of the tubes.
I construct my tubular steam generator or boiler with tubes arranged
in such a manner that they may expand and contract freely with the
variations of heat without injury to the boiler, only one end of each
tube being made fast or permanently secured in a tube plate, the other
end of the tube being left free. The said tubes at the fixed end open
into the chamber, the other end being closed, and I ensure the free
circulation of the water through the said tubes by means of other tubes
placed within the first or outer tubes, such inner tubes being open at
both ends. I construct my improved surface condenser upon the same
principle, that is to say, with tubes fixed at one end and free at the
other end, the fixed end being open and the free end closed, the said
tubes having within them other tubes which are open at both ends, as
herein-after more fully set forth.
In order that my said Invention may be more clearly understood, I a
have given in illustration thereof the accompanying Drawings, which
I will now proceed to describe.

page_text: longitudinal section of a surface condenser constructed according to
my Invention; Figure 3 is a transverse section on the line x, x,
Figure 2. Like letters indicate the same parts throughout the
Drawings.
I will first describe the steam generator or boiler, whereof a is the
chamber, which is arranged at the front end of the said generator or
boiler, and which is divided vertically into two compartments by a
plate b extending from a point near the lowest water level to a point
somewhat below the lowest tube. Into the outer plate c of this chamber
I secure one end of the outer or large tubes d, which thus open into
the compartment a', and I close tightly the other end of the said tubes
with a cap or cover e. These caps are made in such a manner as to
also form the means for supporting this free end of the tubes, while
leaving them free to expand and contract without straining and
weakening any part of the boiler, and causing leakage at the joints or
other parts of the same. The inner tubes are extended through the
compartment a', and secured in the partition plate 6 of the chamber a,
and are supported at their free end within the outer tubes d by pro-
jecting pins or wings g, which hold them central with the outer tubes,
but do not obstruct the circulation of the water therein. The tubes are
placed in an inclined position over the fire, as shewn, in such a manner
that the chamber a is the highest part; the heated gases are therefore
compelled to pass around and among the outer tubes d, the whole of
whose external area forms effective heating surface. As herein-before
stated the ends of the said outer tubes which are secured in the outer
plate of the main chamber open into the compartment a' of the chamber,
and the small tubes open into the return water space a³ of the said
chamber, and as soon as heat is absorbed by the water the circulation of
the latter commences, and the steam generated passes freely into the
steam space a, while the water continually enters and passes through
the inner and outer tubes, as indicated by the arrows.
It will be obvious that as the parts of my improved boiler which
sustain the pressure are of small diameter great structural strength
is obtained, and that as a large heating surface is exposed to the fire
there will be a rapid generation of steam. The construction is simple
and inexpensive, all the material used forms efficient heating surface,
the whole structure consisting mainly of a multiplication of exactly
"

page_text: similar parts. The caps e on the free end of the tubes d are readily
removable, so that the said tubes may be cleaned without difficulty,
and worn out or defective tubes may be easily removed and replaced by
new ones.
My improved surface condenser is illustrated in Figures 2 and 3. The
tubes are secured at one end only, which end is inserted into the
plate c, the other end of the said tubes being closed with the caps e, or
otherwise; this closed end is free to move endwise in its supports, so
that the tubes may expand and contract under variations of heat, while
the free circulation of the water within the tubes d is insured by the
arrangement therein of the small tubes f. In this arrangement of
parts the outer tubes are supported in the sockets h, which support
them properly, while allowing the required longitudinal freedom for
the expansion and contraction of the tubes. The small tubes f placed
inside the said outer tubes d have their end secured in another plate b.
It will be seen that these inner tubes extend nearly to the free end of
the outer tubes d, where they are supported by the pins g, or by other
means which do not impede the circulation of the water through the
tubes. The water enters the condenser at i, flows through the inner
tubes f, and returns through the outer tubes d in a thin sheet or film,
which after absorbing the heat from the steam is discharged from the
condenser by the pipe j. is a partition, which is extended from the
bottom nearly to the top of the condenser. The steam entering at m
passes up between the tubes d over the top of the partition 1, then
passes down among the tubes to the opening n, through which the pro-
ducts of condensation leave the condenser. As only one end of the tubes
is fixed and the other end free no packing is required, and there will
be no breaking of the joints or other injury to the condenser by the
expansion or contraction of the tubes.
Having thus fully described my said Invention, and shewn how the
same may be conveniently and advantageously carried into practice, I
wish it understood that I claim, constructing steam generators and
condensers with tubes fixed at one end in a tube plate (which forms one
side of a chamber divided into two compartments) and free at the other
end when the fixed end of each tube opens into one of the said com
partments and the free end thereof is closed, and when the said tubes
have within them other tubes which are open at both ends and com

page_text: municate with the other compartment of the said chamber, and are
arranged to leave a free passage for the water to circulate through the
inner and outer tubes from one compartment of the chamber to the
other, all substantially as and for the purposes set forth.
In witness whereof, I, the said Joseph Augustus Miller, have herc-
unto set my hand and seal, this Thirteenth day of January, in
the year of our Lord One thousand eight hundred and seventy.
W. A. KIMBALL.
J. A. GROSVENOR.
JOSEPH A. MILLER. (L.S.)